[Crash66]

Ok since I assume your still chasing this, I would suggest you start from the beginning and eliminate the basics first. The ground wire for the AMP needs to be as short as possible and grounded to a very clean bare metal body ground also check the body ground from the battery always worth the time. That wire also needs to be the same guage wire as the power wire if possible. It is very possible it is literally just the amp grounding and to long of a ground wire will cause hum. If that doesn't fix it step 2 would be to start looking at the remote turn on wire coming I assume from the head unit..is it coming from the head unit or are you using a different source to power it? The fact that you say this would be your 3rd amp in this car should tell you there is a major problem in what the amp is getting. It sounds like a ground difference problem to me but on the other hand I would check it all since it is wiping out your amps. My guess is the actual amp ground not being proper but thats a shot from the cheap seats since I am not looking at it! Anyway hope that helps some if not I will watch your response!