What can I legally do if I found out car was in multiple accidents after buying?

I purchased my car, used, from a Mercedes-Benz dealership in the summer of 2015. The vehicle I purchased was not a Mercedes-Benz. Before signing the paperwork, we (my father and I...car is in his name but I pay for it), asked one of the representatives if the vehicle had ever been involved in an accident, to which he said it was never in an accident and he then handed over the CarFax (showed no accident as well). Recently, when trying to switch insurance companies, we discovered that the vehicle was in an accident in 2013 (the insurance provider we were switching to had paid the claim for this accident). I contacted the salesman that I purchased the vehicle from and he provided me with an updated CarFax that showed another accident from 2010. I presume he showed me this information without realizing it was proof that there was a completely separate accident. The CarFax hadn't been updated for 6 years after the 2010 accident and still does not show the 2013 accident. We now have proof that the vehicle was in two separate accidents before we purchased it - none of which were disclosed to us. Furthermore, I've had two other people mention to me (prior to finding out any of this info) that there was a mismatch in the paint between the hood, front fenders, and the doors (my attention to detail isn't too superb so I did not notice). They suggested that the vehicle may have been in an accident but I always referred back to the CarFax whenever the issue was brought up. If two individuals are able to notice these things on my car, shouldn't a dealer be able to spot it as well? Shouldn't the dealer have known, whether it be from its mechanics or salespeople, that this car has signs of being involved.