I have a Sony X-Plode M8800 in my Trans Am I did all the install by myself pretty sure all the wires were tightly put on and black taped yet sometimes ill get this nasty static coming out from my speakers and it wont go away untill the car is completely off and closed . what do u all think it could be? thanx

 

a ground somewhere. They also make filters for the alternator noise but if you didn't have a problem before than you shouldn't have a problem now.

I suggest re-checking your wiring work. Especially the ground and all the power wires (main and remote), etc.

 

if you just twisted and taped wires without soldering or even using a butt connector i'd say fix that first and then go hunting for bad grounds if the noise persists.

 

Ground off somewhere as said before.