I bought my car with an after market stereo install in the ashtray area. It has all new wiring (power, ground, speaker wire, etc). The guy I bought it from took his subs and wiring out and i decided to run my wiring for the amp and sub. After I did this everything worked great, sound was amazing. For the amp ground the PO had one sanded down on the trunk lid that I decided to use. Recently though I have been getting so much electrical interference I haven't even been able to listen to my stereo. I turn it up and I just get this horrible sound. I don't know what it could be, some of my ideas have been the power cable I ran along the drivers side has been interfering with the speaker wire (it also runs on that side) bc the subs don't get the interference just the rears and front components which are all aftermarket. It seems like it only happens on bass hits. My other guess is maybe its where the ground is positioned or I have a bad ground somewhere else (deck idk). So basically I am lost and before I start tearing stuff apart and checking everything I wanted to see if anyone else had this problem or has an idea.