im thinking the seats will work with out the key on, if theres just a battery installed, and the wire harness hasn't been destroyed, a jump box may do it, hell ask the yard to hook up a battery for ya, they want to make sale one way or another.

on another note if you cut the wire harness and start playing touch the wires you may be able to get it to work, make sure you cut the harness after the plug with as much wire as you can cut so you have some room to hook it up to a battery or jump box.