Ok I just installed my 4-channel amp its a US Acoustics USX4065. I have the speaker wires run on both sides of my truck and the power wire run down the middle. My amp is mounted on the plastic behind the the third seat and I have it grounded on the floor pan behind the seat. At first I thought the wine was from my power wire too close to my speaker or RCA cables but I checked and they had plenty of distance. Then I came to the conclusion that it was my ground. So I moved my ground from under one of the bolts that secures the third seat to the floor pan behind the seat. I sanded down the paint until I saw the nice shiny metal and then mounted it. There are two things left that I think it could be tell me what you think. My ground wire is 3ft which from what I read is pretty damn long so I am thinking of cutting that down. Second I have the ground wire secured with a small self tapping screw and I read that I should use a 3/8in. bolt. Tell me what ya think.