I've been searching where those annoying vibrations come from when my sub (12" in the stock location on an SC400) plays at certain frequencies. Still have a hard time believing it, but it appears to be the rear window (everytime I press against it, the vibrations stop). Anything I can do about this besides dynamatting the window

Thanks

 

It may be the brake light indicator hitting the window. Try putting some thin rubber or something similar between the rear window and the brake light indicator. When I took out the Nak free air sub and put a new sub and amp in the trunk mine (GS400) did the same thing.

 

No third brake light here ...