Hey i have some noise problems with my subs that may be ground loops or emi well my rca's r not by my power wire, my speakers wires r not by the power wire, it usually makes rumbling sounds thru the speakers when the cd player is loading a cd. I eliminated it a little bit by grounding the cd player to metal and not using the factory ground. My amp is grounded to bare metal but it is on a tailight screw. Now when i use any thing like the window or turning on the headlights or using the turn signal you can hear it thru the speakers just wondering if grounding the amp to that spot would cause that. Also could my problems just be emi possibly being picked up by the rca's?
Taillight screw? ummm.... that doesn't sound too nifty. How long a ground wire do you have? I'd try and find a place on the chassis "near" the amp where you can drill yourself a hole for a good ground screw.
Be careful of gas tanks or other sensitive items on the other side of that hole tho.