Oh, sure, Large One, add something to my own trivia question that I don't know!
I'll take a stab at it: One of the cars was powered by a rotary engine?
Seriously, no one is going to take a stab at this? Here's a hint: The mercurial progress of the car in question was not due to any substantive (i.e., mechanical) modifications, but rather to a "cosmetic" one...