"The bear was so determined to enter the car, it ripped off its back bumper."

No.  That is the bear being mildly interested.  If the bear were actually determined to enter the car, it would have entered the car.  My aunt, from the bedroom of her house, watched a bear put a paw through the screen door and front door of the house, and rip both doors completely off the frame.  It then entered the house, found, and ate the ginger snaps in the kitchen cabinet.  A car door/window is not stopping a bear.