I have come across an ad for a local 91 M5, claimed 124K miles, temptingly priced. Haven't seen the car yet. Problem is it's being sold by a small used car dealership, meaning it's likely an orphan bought at auction, no paperwork, etc. Is there anything that a good indie shop familiar with M cars can do to assess the general health of the S38, short of a complete teardown? Too big a gamble?

Thanks for your insights.