The only thing that I could think of regarding the installation is perhaps an improperly grounded amp; currently it's bolted to the chassis via the rear strut bar, which is painted.

Well, if the amp doesn't have a ground wire connected properly, that'd be a start. It should have a specific ground screw that's wired to a ground point (such as an unpainted bolt to the chassis). Amps shouldn't ground through their casings.

You're not trying to DRIVE the amp from the remote-control wire, are you? The amp should have a direct wire (preferably heavy gauge) going straight to the car battery, via a weatherproof fuse connection. That, plus the ground wire, plus the amp remote control wire, are the three electrical connections the amp should be making.

If you find that this isn't wired correctly, I highly recommend you take the car to a professional installer and have them re-do the wiring from the ground up, since who knows what else is wrong at that point...

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Tony Fabris