Our 3 year old Ford Demo Purchase - was in a rear end accident

[Hemihunter]

We purchased this 3 years ago from a Ford Dealer knowing it was a Demo with 2,500 klms, still under factory warranty, turns out the car has had a rear end accident before we purchased it, is this something the dealer should have advised before purchase? do we have any recourse on the dealer at all? Haven't bought it to the dealers attention as yet, just curious how to proceed.