[sambo]

I kind of agree re simplifying things. With a portable music player you have two loose wires in the cabin - the charge wire and the signal feed to the boot. Plus you have to secure the device so it doesn't slide around. Then remove it from view whenever you walk away from the car.

I'm planning just to have a decent head unit in the boot with a 64Gb SD card holding my entire music collection and a remote screen somewhere in the cabin. Amps can be added later if more juice is required.