[thstone]

The exhaust is unlikely to provide +30hp, but if it does it will be guaranteed to be so loud that every policeman will be aware of your location within three blocks. More likely is +10 to 15hp and only at the very highest RPM's.

Any idea of what components comprise the "racing suspension"? It could have anything from a lowering spring to a full race set up but without details its hard to provide much feedback.