My older stand alone amp had a seperate line in to turn on and shut off the amp with the ignition or a fuse source.Felix said:It sounds like you're trying to do something like what I've got in mind, which is use only an MP3 player (iPod in my case), amp and speakers. Or if you can find powered speakers of some kind, you wouldn't need the amp, I guess, but I'd question your ability to hear anything on the road.
If you get an amp and some speakers, you should be able to run the MP3 player direct to the amp with a mini plug-to-rca cable adapter. You could then just disconnect the player and take it with you.
The only hurdle I'm trying to overcome is wiring the amp so that it turns off when the truck does. Without the use of a head unit, you lose the ability to connect the remote wire from the amp to the deck that tells the amp to shut off when the deck does.