Agreed, I don't think it's that
crazy - had the same thought recently... but then again - maybe I am crazy
Any sounds by the crowds in general would do much for atmosphere/immersion imho. Even if it's just some "wooohoo" or "go go go" or some loud whistling as you drive by some close spectators.
Ideally they would even turn your car back on the wheels if you happened to crash and lie on your side or on the roof, but that's probably not going to happen.