Man, I'm not sure I'm getting what you want... You want an amp without wiring it? I mean, You have to wire it to the battery to get power, and to the HU to get audio signal, right?
what im saying is. i need to know if there is an alternative way to hook up the remote wire from the amp besides going to the head units power antannea, or ignition switch. i dont want to remove my hu because its a pain in the a$$.
The only alternative i see is have an electronics brain build you an FM-activated flip-flop controlled relay to switch the REM from the power line, but I guess that'de would be too much hassle, forget it. Maybe GlassWolf knows of something! Good luck!