My bmw x5 2017 hit my garage door after i put it in park mode. i believe that it was caused by its transmission problems and the failed handbrake. on that night, i stopped my car on a slightly inclined driveway. i turned on the handbrake, put the car in park mode, turned off the engine, and then stepped out of the car. about 10 seconds later, the car rolled forward and hit my garage door. it was snowing that night, but the snow was less than one inch. the car didn't slip because the four wheels rolled forward. i tested it a few times right after the incident and the car still rolled forward with the handbrake on and after shifting to p mode. the transmission and handbrake failed to work several times on that night, but i cannot re-generate the same result since that night. when i searched for similar cases online, i found that a bmw x5 2012 had the same issue in 2013. bmw denied that my car has any issues after inspecting it, it is the same response to the case in 2013. this car is unsafe for pedestrians and drivers. we never know when the transmission and handbrake will fail to work properly. it happened once, and it can happen again anytime, anywhere.