interesting question here. i wanted to install a system that would be easy to remove from a 98 merc sable.used speaker boxes w amp bolted to it and used high level outputs from factory tuner. this setup blew up 3 amps[you'd think i would've learned after the first one blew but i had spare amps so i just kept replacing]. amps varied from pioneer to sanyo to alpine. The really weird thing here is that it sounded fairly good and amp would only blow up after i left car at the airport for a few days...overnight would be ok. I'll bet if i installed a switch in the power cable i would have been ok but all i want to know is why???? thanks in advance
forgot to mention what i mean by blowing up. what happens is it works fine unless you leave car parked for a few days. if left off after afew days when you get in car and turn on stereo you'll get a slight pop and amp fuse will blow. once this has happened the amp is screwed. fixed it once and the left channel had blown.