DO NOT leave your speakers and headunit in there. if your car's not at the bodyshop yet, take it out ASAP...or atleast b4 the car goes into the shop. When someone hit my car ('90 Acura Legend) I had a Pioneer headunit, 4 infinity speakers, 1 12" infinity sub, and a RF amp in the car. I didnt know any better and took it to the body shop to get a quote on fixing it. When the insurance adjuster came, they declared my car totalled.
But since my aftermarket audio equipment wasnt insured, I wanted to take it out and replace it with the stock stuff before they took my car away. This is where the problem started. Insurance company wouldnt let me take the car off the body shop's lot without calling it a buyback, and the bodyshop wouldnt let me get into my car and take stuff out on their lot (apparantly they were scared of getting sued if i were to get injured on their property while taking the stuff out). It was a real PITA that lasted about 2 weeks...but I persisted and finally got my way - insurance company let me drive the car back to my place where I took my stuff out...and a tow truck came and picked up my car from my house.