The Special, Non-moving Car Part
RAY: The bottom of every tire is moving at zero miles an hour with respect to the road. If that weren't the case, then the car would be in a skid.
Imagine an ideal tire where one point is touching the road. That very point of the tire that's touching the road must not be moving in relation to the road. In fact, it is moving at zero miles an hour. And when you point it 180 degrees away, it has to be moving at twice that speed, or 120 miles an hour.
Do we have a winner?
TOM: You bet we have. It's Alan Hayashi, from Oxnard, California. And for having his answer selected at random from among all the correct answers that we got, Alan is going to get a 26-dollar gift certificate to the Shameless Commerce Division at cartalk.com, with which he can get a brand spanking new red, grey, and black Car Talk baseball shirt, which has that scripty baseball lettering on the front and says, "Car Talk Plaza." It makes a wonderfully absorbent oil rag if you're too embarrassed to wear it.
[ Car Talk Puzzler ]