It was really windy last weeked, the same thing happed to my sisters car. She hit the car next to her when she opened the door. Luckily it was a crappy car next to her and the owner didn't really care. Which part broke off? That black part is like $29, but you are probably having alignment issues.
CHECK LINK ASSY-FRONT DOOR RH - 370Z (Z34) 2009+ :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com
