installed mac pro chamber with my bassani axle backs and there is a loud rattling sound coming from the right rear speaker area or the quarter panel sounds like a license plate vibrating from bass from a system but this is from the exhaust,thought it may be one the hangers but there all tight ,sounds more like its in the rear trunk area anybody have any ideas whut it could be? thanks

 

Yea, I had a similar problem... Apparently when they installed my prochamber, it shifted the pipe going over the axle back just enough to cause a similar vibrating issue... The pipe was hitting the spare tire well during acceleration and deceleration... Under no load condition, there was about 1/8" gap between the pipe and the spare tire well...It took me a few days to find it... I also thought at first it was my license plate, my rear bumper itself or the spare tire/jack, but it wasn't... Hope you can find it... it was very annoying until I got it fixed...

 

that wasnt it just went and looked all pipe all plenty of clearance all the way back,the sound is like right behind the right side window in the speaker area or sumthin like 2 pieces of metal flapping against each other sounds pretty lose w/e it is but i checked everything i could see felt nothin loose

 

Just a thought. There have been comlaints about noises from the rear quarter panels before on some cars, but probably earlier builds. You might try a search. The easiest solution would be to have someone drive your car while you lay in the trunk area with the seats down to isolate the noise. The way noises travel, they can be very difficult to isolate.

 

found source right rear exhaust hanger, the hanger on muffler is hitting the hanger that colts to car