What state are you in? You need to find an attorney you paid for.
There are many steps available to you.
3. Court action
Notice that NOT one of those steps above is "rolling over" as your "friend" suggests".
Don't want to hire competent legal counsel. Take your bike, with a giant sign stating your plight with this dealership/BMW, and park your a*s just off of their property, with a cooler full of water/snacks, and sit and wave at people encouraging potential customers to stop and talk with you. Many ways to skin a cat my friend and most of them will cause you great inconvenience.