OK, let me get this straight, not trying to be an ass here but you've got $800 worth of equipment in your car and you've only got liability insurance? :doood: :wtcslap:
Comprehensive insurance is not that much. I can understand why you'd drop collison and you need liability of course but comprehensive is like chump change compared to what you pay for liability. Sorry, I just don't understand why some people put expensive ass stereos in their cars and no insurance to cover it.

As for your door, who knows? You might try your local junkyard to see if they have one but I'd go to a body shop first to see what they'd charge to fix it.