help sqeaky
The subs will make your taillights and everything else bolted to the back of the car vibrate like crazy. I did a lot of sound proofing to mine so it would sound like the car was going to fall apart and I wasn't puching anywhere near 1200 watts! Good luck
Panhard and LCA bushings and the sway bar endlinks. All
of these can squeak when dry, a graphite loaded grease
is a good way to go (I use engine assembly lube, with the
graphite & moly in it).

