What was the nature of the accident and where was the damage? In my experience, body shops are notorious for the lack of understanding of mechanical or electrical things.

E.g. a Plymouth Sundance my wife had went into the body shop after an accident, and when we got it back the battery kept discharging. Several returns later, and scratching their heads was the best they could manage. I checked a Haynes manual, found the computer - which contains the alternator regulating circuit - was located in the fender that had been involved. A quick trip to the local dealer shop and renegotiation with insurance solved the problem.

Steve