Hi Sam. Technically a dealer does not have to tell you about minor damage to a new car (it’s relatively common during transit or when they’re in storage). However, if the dealer or leasing company has lied to you about what happened, then they have a case to answer.
It can get difficult to argue the details, because it depends on exactly what you were told and by whom. If you specifically asked if the car had been in an accident and they said no, it’s pretty clear (although verbal assurances are almost worthless). However, if there is any wiggle room where they didn’t lie to you because you didn’t ask the right question, it’s very grey.