Paint happens, and this could have happened after you took delivery.

But I would be pretty upset that the dealer couldn't refrain from damaging it until you got it...or at least fix it before you knew about it! (Many new cars are damaged in transit and dealers/BMW repairs them pre-delivery.)

Your choices are limited:
1. Refuse delivery, ask for an undamaged car.
2. Accept it as repaired.

With either option you can request some kind of compensation... indeed, initially picking #1 and moving to #2 might maximize that aspect....

But I assume that once you take delivery, your bargaining power is zero.

GL

A