Car Talk was presented in the form of a call-in radio show: listeners called in with questions related to motor vehicle maintenance and repair. Most of the advice sought was diagnostic, with callers describing symptoms and demonstrating sounds of an ailing vehicle while the Magliozzis made an attempt to identify the malfunction over the telephone and give advice on how to fix it. While the hosts peppered their call-in sessions with jokes directed at both the caller and at themselves, the Magliozzis were usually able to arrive at a diagnosis. However, when they were stumped, they attempted anyway with an answer they claimed was "unencumbered by the thought process", the official motto of the show.
Edited reruns are carried on XM Satellite Radio via both the Public Radio and NPR Now channels.
The Car Talk theme music was "Dawggy Mountain Breakdown" by bluegrass artist David Grisman.
Throughout the program, listeners were encouraged to dial the toll-free telephone number, 1-888-CAR-TALK (1-888-227-8255), which connected to a 24-hour answering service. Although the approximately 2,000 queries received each week were screened by the Car Talk staff, the questions were unknown to the Magliozzis in advance as "that would entail researching the right answer, which is what? ... Work." Producers selected and contacted the callers several days ahead of the show's Wednesday taping to arrange the segment. The caller spoke briefly to a producer before being connected live with the hosts and was given little coaching other than being told to be prepared to talk, not to use any written preparation and to "have fun". The show deliberately taped more callers than it had time to air each week in order to be able to choose the best ones for broadcast. Those segments that did make it to air were generally edited for time. For the last four years of the show, new shows included previously broadcast segments as much as 10 years old. The re-used segments, including re-used puzzlers, were not acknowledged as old material and sometimes new caller material was mixed in alongside the recycled calls.
The show originally consisted of two segments with a break in between but was changed to three segments. After the shift to the three-segment format, it became a running joke to refer to the last segment as "the third half" of the program.
The show opened with a short comedy segment, typically jokes sent in by listeners, followed by eight call-in sessions. The hosts ran a contest called the "Puzzler", in which a riddle, sometimes car-related, was presented. The answer to the previous week's "Puzzler" was given at the beginning of the "second half" of the show, and a new "Puzzler" was given at the start of the "third half". The hosts gave instructions to listeners to write answers addressed to "Puzzler Tower" on some non-existent or expensive object, such as a "$26 bill" or an advanced digital SLR camera. This gag initially started as suggestions that the answers be written "on the back of a $20 bill". A running gag concerned Tom's inability to remember the previous week's "Puzzler" without heavy prompting from Ray. For each puzzler, one correct answer was chosen at random, with the winner receiving a $26 gift certificate to the Car Talk store, referred to as the "Shameless Commerce Division". It was originally $25, but was increased for inflation after a few years. Originally, the winner received a specific item from the store, but it soon changed to a gift certificate to allow the winner to choose the item they wanted (though Tom often made an item suggestion).
A recurring feature was "Stump the Chumps," in which the hosts revisited a caller from a previous show to determine the accuracy and the effect, if any, of their advice. A similar feature began in May 2001, "Where Are They Now, Tommy?" It began with a comical musical theme with a sputtering, backfiring car engine and a horn as a backdrop. Tom then announced who the previous caller was, followed by a short replay of the essence of the previous call, preceded and followed by harp music often used in other audiovisual media to indicate recalling and returning from a dream. The hosts then greeted the previous caller, confirmed that they had not spoken since their previous appearance and asked them if there had been any influences on the answer they were about to relate, such as arcane bribes by the NPR staff. The repair story was then discussed, followed by a fanfare and applause if the Tappet Brothers' diagnosis was correct, or a wah-wah-wah music piece mixed with a car starter operated by a weak battery (an engine which wouldn't start) if the diagnosis was wrong. The hosts then thanked the caller for their return appearance.
The brothers also had an official Animal-Vehicle Biologist and Wildlife Guru named Kieran Lindsey. She answered questions like How do I remove a snake from my car? and offered advice on how those living in cities and suburbs could reconnect with wildlife.
Celebrities were featured as "callers" as well, including Geena Davis, Morley Safer, Ashley Judd, Gordon Elliott, former Major League pitcher Bill Lee, and astronaut John M. Grunsfeld calling from the Space Shuttle. There were numerous appearances from NPR personalities, including Bob Edwards, Susan Stamberg, Scott Simon, Ray Suarez, Will Shortz, Sylvia Poggioli, and commentator and author Daniel Pinkwater. On one occasion, the show featured Martha Stewart as an in-studio guest, whom the Magliozzis twice during the segment referred to as "Margaret".
In addition to at least one on-orbit call, the Brothers once received a call asking advice on winterizing an electric car. When they asked what kind of car, the caller stated it was a "kit car", a $400 million "kit car". It was a joke call from the Jet Propulsion Laboratory concerning the preparation of the Mars rover for the oncoming Martian winter. Click and Clack have also been featured in editorial cartoons, including one where a befuddled NASA engineer called them to ask how to fix the Space Shuttle.
Humor and wisecracking pervaded the program. Tom and Ray are known for their self-deprecating humor, often joking about the supposedly poor quality of their advice and the show in general. They also commented at the end of each show: "Well, it's happened again—you've wasted another perfectly good hour listening to Car Talk."
At some point in almost every show, usually when giving the address for the Puzzler answers or fan mail, Ray mentioned Cambridge, Massachusetts (where the show originated), at which point Tom reverently interjected with a tone of civic pride, "Our fair city". Ray invariably mocked "'Cambridge, MA', the United States Postal Service's two-letter abbreviation for 'Massachusetts"', by pronouncing the "MA" as a word.
Preceding each break in the show, one of the hosts led up to the network identification with a humorous take on a disgusted reaction of some usually famous person to hearing that identification. The full line went along the pattern of, for example, "And even though Roger Clemens stabs his radio with a syringe whenever he hears us say it, this is NPR: National Public Radio" (later just "... this is NPR").
At one point in the show, often after the break, Ray usually stated that: "Support for this show is provided by," followed by an absurd fundraiser.
The ending credits of the show started with thanks to the colorfully nicknamed actual staffers: producer Doug "the subway fugitive, not a slave to fashion, bongo boy frogman" Berman; "John 'Bugsy' Lawlor, just back from the ..." every week a different eating event with rhyming foodstuff names; David "Calves of Belleville" Greene; Catherine "Frau Blücher" Fenollosa, whose name caused a horse to neigh and gallop (an allusion to a running gag in the movie Young Frankenstein); and Carly "High Voltage" Nix, among others. Following the real staff was a lengthy list of pun-filled fictional staffers and sponsors such as statistician Marge Innovera ("margin of error"), customer care representative Haywood Jabuzoff ("Hey, would ya buzz off"), meteorologist Claudio Vernight ("cloudy overnight"), optometric firm C. F. Eye Care ("see if I care"), Russian chauffeur Pikup Andropov ("pick up and drop off"), Leo Tolstoy biographer Warren Peace ("War and Peace"), hygiene officer and chief of the Tokyo office Otaka Shawa ("oh take a shower"), Swedish snowboard instructor Soren Derkeister ("sore in the keister"), law firm Dewey, Cheetham & Howe ("Do we cheat 'em? And how!"), and many, many others, usually concluding with Erasmus B. Dragon ("Her ass must be draggin'"), whose job title varied, but who was often said to be head of the show's working mothers' support group. They sometimes advised that "our chief counsel from the law firm of Dewey, Cheetham, & Howe is Hugh Louis Dewey, known to [group of people] in Harvard Square as Huey Louie Dewey." Huey, Louie, and Dewey were the juvenile nephews being raised by Donald Duck in Walt Disney's Comics and Stories. Guest accommodations were provided by The Horseshoe Road Inn ("the horse you rode in").
At the end of the show, Ray warned the audience, "Don't drive like my brother", to which Tom replied, "And don't drive like my brother." The original tag line was "Don't drive like a knucklehead." There were variations such as, "Don't drive like my brother ..." "And don't drive like his brother", and "Don't drive like my sister ..." "And don't drive like my sister." The tagline was heard in a cameo for the Pixar film Cars, in which Tom and Ray voiced anthropomorphized vehicles (Rusty and Dusty Rust-Eze, respectively a 1963 Dodge Dart V1.0 and 1963 Dodge A100 van, as Lightning McQueen's racing sponsors) with personalities similar to their own on-air personae. Tom notoriously once owned a "convertible, green with large areas of rust" Dodge Dart, known jokingly on the program by the faux-elegant name "Dartre".
In 1977, radio station WBUR-FM in Boston scheduled a panel of local car mechanics to discuss car repairs on one of its programs, but only Tom Magliozzi showed up. He did so well that he was asked to return as a guest, and he invited his younger brother Ray (who was actually more of a car repair expert) to join him. The brothers were soon asked to host their own radio show on WBUR, which they continued to do every week. In 1986, NPR decided to distribute their show nationally.
In 1992, Car Talk won a Peabody Award, saying "Each week, master mechanics Tom and Ray Magliozzi provide useful information about preserving and protecting our cars. But the real core of this program is what it tells us about human mechanics ... The insight and laughter provided by Messrs. Magliozzi, in conjunction with their producer Doug Berman, provide a weekly mental tune-up for a vast and ever-growing public radio audience."
In May 2007, the program, which previously had been available digitally only as a paid subscription from Audible.com, became a free podcast distributed by NPR, after a two-month test period where only a "call of the week" was available via podcast.
As of 2012, it had 3.3 million listeners each week, on about 660 stations. On June 8, 2012, the brothers announced that they would no longer broadcast new episodes as of October. Executive producer Doug Berman said the best material from 25 years of past shows would be used to put together "repurposed" shows for NPR to broadcast. Berman estimated the archives contain enough for eight years' worth of material before anything would have to be repeated. Ray Magliozzi, however, would occasionally record new taglines and sponsor announcements that were aired at the end of the show.
The show was inducted into the National Radio Hall of Fame in 2014.
Ray Magliozzi hosted a special Car Talk memorial episode for his brother Tom after he died in November 2014. However, Ray continued to write their syndicated newspaper column, saying that his brother would want him to.
The Magliozzis were long-time auto mechanics. Ray Magliozzi has a bachelor of science degree in humanities and science from MIT, while Tom had a bachelor of science degree in economics from MIT and an MBA and DBA from the Boston University School of Management.
The duo, usually led by Tom, were known for rants on the evils of the internal combustion engine, people who talk on mobile phones while driving, Peugeots, women named Donna who always seem to drive Chevrolet Camaros, lawyers, the clever use of the English language, people who choose to live in Alaska (or similar snowy, icy climates), and practically anything else, including themselves. They had a relaxed and humorous approach to cars, car repair, cup holders, pets, lawyers, car repair mechanics, SUVs, and almost everything else. They often cast a critical, jaundiced insider's eye toward the auto industry. Tom and Ray were committed to the values of defensive driving and environmentalism.
The Magliozzis operated a do-it-yourself garage together in the 1970s which became more of a conventional repair shop in the 1980s. Ray continued to have a hand in the day-to-day operations of the shop for years, while his brother Tom semi-retired, often joking on Car Talk about his distaste for doing "actual work". The show's offices were located near their shop at the corner of JFK Street and Brattle Street in Harvard Square, marked as "Dewey, Cheetham & Howe", the imaginary law firm to which they referred on-air. DC&H doubled as the business name of Tappet Brothers Associates, the corporation established to manage the business end of Car Talk. Initially a joke, the company was incorporated after the show expanded from a single station to national syndication.
The two were commencement speakers at MIT in 1999.
Executive producer Doug Berman said in 2012, "The guys are culturally right up there with Mark Twain and the Marx Brothers. They will stand the test of time. People will still be enjoying them years from now. They're that good."
Tom Magliozzi died on November 3, 2014, at age 77, due to complications from Alzheimer's disease.
The show was the inspiration for the short-lived The George Wendt Show, which briefly aired on CBS in the 1994-1995 season- as a mid-season replacement.
In July 2007, PBS announced that it had green-lit an animated adaptation of Car Talk, to air on prime-time in 2008. The show, titled Click and Clack's As the Wrench Turns is based on the adventures of the fictional "Click and Clack" brothers' garage at "Car Talk Plaza". The ten episodes aired in July and August 2008.
Car Talk: The Musical!!! was written and directed by Wesley Savick, and composed by Michael Wartofsky. The adaptation was presented by Suffolk University, and opened on March 31, 2011, at the Modern Theatre in Boston, Massachusetts. The play was not officially endorsed by the Magliozzis, but they participated in the production, lending their voices to a central puppet character named "The Wizard of Cahs".