they use 60% of its value, so that will get written off. They just value it based on book value, not retail, which is a bit crap. With the floor buckled i'ts not gonna be a cheap fix to do it properly. i'd be tempted to just strip it, but personaly i wouln't put it back ont he road, just not wirth the cost.
as far as getting the car back, if its a 3d party, aka not your insurance, paying out then the car still belongs to you to do as you please.