BMW Full Check-up

I had an accident last week & my car is in the body shop. It's getting repaired right now - the front grill, head lamps etc. are getting replaced. However, my biggest concern is about all the other things which might have gone wrong and not identified now & hence not fixed.

I wouldn't have worried about it much if not for my warranty expiring next month. Wondering if there is any full check-up kinda thing where I can get my car inspected and checked completely..

I called the dealer up here in NJ & he says "there is no full check-up sort of thing. The car runs its self diagnostic and if anything is wrong it should come up.".. I understand what he is saying, but i'm not very confident that the self diagnostic tool would identify any potential problems which can be identified by a good tech./service engineer.

Any suggestions on what can be done?

I also asked for the cost for extending my warranty, the dealer quoted me $4000+ for warranty and $2000+ for maintenance package. I don't have the budget to spend 4K on warranty but i'm also afraid something might come up later which might cost me a lot more.. :-(

09 335i XDrive Sedan
39K miles.