what do nascar drivers do when the must pee during a race?

Answer 1

They just go. Usually they race in warm conditions so they sweat a lot of fluids out. If they have to go it wouldn't amount to a whole lot so they just go. Normally, though, when your adrenaline is pumping and you are focused and/or engaged in a sporting activity, you won't feel the urge to go.

Answer 2

Yeah, the insides of those race cars get up to 140 degree's on a good day, so they don't really have to worry about peeing too much in those conditions.