RAY: Now, a lot of people wrote in and said things like, "the air in the tires," "the oil in the crankcase."
TOM: But we said it was an actual mechanical part -- not a fluid. We did research this for six or seven minutes.
RAY: The answer is the Schrader tire valve, the valve that goes in the stem.
TOM: It's called that because it's made by the Schrader Company. It's not a Schrader-type valve.
RAY: It's the little valve that screws, and keeps the air from coming out. It's a little check valve, and it allows you to put air into the tire, yet it does not allow air to escape.
TOM: A check valve? I thought they made them in Czechoslovakia.
RAY: You can take that out of any car. In fact, we've taken them out of all the cars in the parking lot... and all the cars in the parking lot now have flat tires.
[ Car Talk Puzzler ]