I'm having a really loud banging sound from under my 07 h3. Sounds like something Metal wrapped around the driveshaft hitting something metal. Only have that when driving not when sitting. The faster you go the faster it go's anf the worse it sounds. I was thinking the u joint's but I can't move them by hand so idk I'm lost as to where to star. ANY HELP WOULD BE GREAT.... THANKS IN ADVANCE

 

heat shield? Also check the exhaust there is a bracket that can break that causes a loud metal vibration sound

 

Exhaust heat shield can break and make contact with the rear drive shaft. Get under there and LOOK.

 

Thanks for the advice but I have been all over underneath it and looked at all the heat shields and nothing is loose( at least in that part). But I laid under it and had my wife back up and come back over me. On the front Differential there is a mount . The mount is worn out and the differential jumps forward. I know it has to be fixed but would that be what is making that sound?