It is the amp, Poor location. Make sure the drain tube isn't blocked or misdirected, Check the trunk seal, Water gets in the amp location and fries them. You have to waterproof the amp.
I,too, have had the same problem. I have a '92 SC 400. Up until this year, never had a problem with water intrusion. A year ago the quarter panel on that side was replaced. I returned to body shop, who'll gratefully take responsibility for a potential leak and replace the amp, too. Body shop did some checking and heard from their source at a car stereo shop of a recent spate of leaks and fried amps. Curious what is involved with water proofing an amp?
