Tom and Ray Magliozzi, better known as Click and Clack the Tappet Brothers of Car Talk fame, are calling it quits on their popular NPR radio show, the duo announced Friday.

After 25 years of broadcasting at NPR -- 35 years of broadcasting overall -- the brothers said on the show's website that with Tom turning over the birthday odometer to 75, we've decided that it's time to stop and smell the cappuccino.

Ray jokingly added that now that they are retiring from the radio business, they could finally answer the question, If my brother retired, how would he know? Tom and Ray said retirement is a natural progression of their lifelong philosophy to make work afraid of you.

Car Talk will stop making new shows in the fall, but it will continue to be broadcast regularly via a pool of 1,200 recorded programs. Each week, NPR will broadcast a Car Talk episode compiled from archival material. The brothers ruled out a possible return to the show, but they did say they would continue writing their Dear Tom and Ray column for the website as well as clanging pots in the office to make sure our staff is awake at least two hours a day.

Close to the end of their broadcasting run, Click and Clack the Tappet Brothers have managed to avoid getting thrown off NPR for 25 years, given out tens of thousands of wrong answers, generated lawsuit threats from innumerable car companies, and had a hell of a lot of fun, Ray said.

Listeners commenting at the Car Talk website expressed their sadness at the end of an era of gearhead entertainment. Their words pull at the heartstrings.

Come on guys! You are part of American Culture! You may as well rip up the Constitution. ... Now what's going to happen to the Time Space Continuum. I can see it now. All the cars in America stopped dead unable to function without your Input, commenter Dingo wrote.

Another commenter, Madiha, echoed those words: Hope you WILL change your mind when you get tired of doing nothing, Tom ... Saturday mornings won't be the same.

At the end of a spectacular run, Tom and Ray will leave NPR and automotive enthusiasts -- and people stuck by the side of the road or trying to figure out how to get a squirrel out of the transmission -- missing their wisecracking advice and genuine insight  into cars, human nature, and the silliness that results when the two are combined.

I learned more about cars, and people, than I ever intended to. Thank you, thank you for what you have done for all of us, wrote jaggret.