Please tell us more about the mechanical condition of the car and if you have done any mods.
250k is getting up there. Not a big deal if well maintained and you have gone through the 200k replacement cycle of crap that breaks every 100k.
Even if you find replacement body parts the same color, they won't really be the same color. Is that going to bug you? I think it was romus that was complaining that he realized his car is three different shades of red as a result of fender benders in the hands of the prior owner. Paint jobs are obscenely expensive. Also are you sure that all the mechanical stuff behind the messed up wheel is ok?
One strategy a lot of people do is strip the car of mods and then let the insurance company total it. If you get a good settlement from the insurance company it can be an opportunity to get the car you wish you had gotten after becoming more knowledgeable about e34s like getting a 535 or a manual or one with better paint etc.
So sorry this happened to you but maybe something good will come out of it.
I assume you saw the other thread that is going on with similar issues.
http://www.bimmer.info/forum/showthread.php?t=17240
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