I've posted a similar topic in a few other forums but haven't really reached a conclusion. Anyhow it seems when i take off i here something like a exhaust leak like a "dun dun dun dun" (it gets higher at higher speeds then kinda goes away) but i dont see any holes anywhere that i know of. Also it happens then goes away after driving for a while, it's not my belts they've all been changed recently plus it was doing this before that, my car is really low but it's not the tires hiting anything i know that sound pretty well. any suggestion would be greatly apperciated.

 

souned like your exhaust hitting again fuel tank or heat shield..

 

anyone else???!