Yeah no shit. The thing is, those supercars are insanely loud from factory. I was behind a pair of Diablo SVs in a traffic jam on the motorway once, and even then they pretty much drowned out the sound of the little 500 cc motorcycle engine between my legs. I have no idea how those things are deemed street legal.

Edit: It's not about the revs alone, but also engine load. 3000 rpm stationary might be relatively quiet, but 3000 rpm with the throttle blades wide open is an entirely different matter.