Hey guys I'm trying to figure out where to ground my amp. I really can't see any screws in my trunk. I took out the carpet and stuff and I just see rivets and weld points. Is there some spot that I'm missing? There's 1 screw i see but I can/t get to it. It's holding the backseats in place at a weird angle and it's too big for my ring thing. I'm using 8 gauge knuckles kit.