I just came back from watching the USGP. There was a black Enzo there. The owner started it up. Then he revved it. Wow. Did it sound sweet! One other thing, the hood was up. The engine did NOT vibrate at all. Just by looking at the engine, one would think it was off but it was not. Talk about smooth.
This happened to be a replacement Enzo. The original one was destroyed at Monza.