My 300SD has been in a rear-ender sometime in it's past. The left rear taillight has the wrecking yard numbers still on it when you look at it from inside the trunk. Also can see evidence of wrinkled sheet metal inside the trunk if you pull away the inside panels. The left rear door has a funny bow to it. The rear bumper is a bit crooked. There's other indicators, but I'm still happy with it. It goes down the road straight, and the PO did a lot of mechanical repairs to it, and it's really in good shape, especially for a car with over 300k on it. So a past accident I don't feel is an immediate reason to not buy a car. Depends on how well it was fixed, and whether you want a decent looking, dependable daily driver, or a show car that's totally flawless that you are going to be afraid to drive on the road.
My opinion