I had two minor collisions in my 1998 C230 (neither were my fault) I took my car to Wagonworks in Arlington(?) - not too far from National Airport. or Crystal City.
Both times Wagonworks located all the faulty areas and contacted the insurance company to amend the insurance companies work order.

From my experience, Insurance companies do a very cursory evaluation, and since Wagonworks has a good reputation the insurance co. agreed to all the additional work.

A search will find some older articles on accident and insurance companies.
I also know that some people say Wagonworks is overrated and some ex-Wagonworls employees opened a new shop in or around Rockville.

There are some good repair shops around D.C..