Hm, no, in F1 they don’t have the same car. Each season, each team builds their own (adhering to the Formula) and put massive amounts of efforts to gaining efficiency through engineering.
My eyes being rolling faster than my crank...
I don't really follow NASCAR, but from listening to my (huge fan) father-in-law, that word is doing some work. His best (or, at least, my favorite) are the creative ways teams find to bend the rules - or blatantly cheat! - to give their cars an advantage.
One that made me laugh: a team once packed their suspension tubes with lead shot to make minimum weight. On the first lap the driver pulled a lever that dropped all the shot onto the track, and then enjoyed an underweight car for the rest of the race! They're always looking for "legitimate" optimizations, too.