Art,
I think I had the same problem a while back, when my SRS light came up out of the blue- I was feeding a 3V portable CD player with an adapter from the cigarette lighter, and at the same time had tapped in the wires to the amp of the SR 7145 made by Alpine- at least the chips say so, eventually I ended up buying few NiMh rechargeable D series bat. and a cage, so I have enough A/H to play for 9-10 hours, and then simply replace them- the advantage is very clean sound compare to ac adapter and if I ever run out of batteries- just put the regular D series from the gas station. Of course the biggest disadvantage is that you constantly have to monitor or change your rechargeable, I wish I had 2 banks- one hooked up to the car 12 V system and one playing the ipod or AUX device, and a switch- which will put one of the banks for charging and the opposite for powering, you don't have to spend too much money for that, you can even go with couple of AA rechargeables in each bank, that's just an idea. Right now I am using a $20 MP3 player which feeds the music trough the FM, and I hate it, I will definitely, find a solution, I hate the extra noise from that.
Regards,
Alex