This troper has been on the receiving end of this trope, only offset by a few inches and clipping the back corner of the car instead of smacking into the door, as well as just plain cycling into the back of a car and sliding off the back.

This troper's father tells a story of how while riding his bike down a hill, he was forced to dodge a car door opening. This sent him out of control towards a barbed wire fence. He missed the barbed wire, but smashed his head on a post instead.

This troper managed to avoid the bulk of the door, but clipped the sharp edge (car doors have a sharp edge?!?) with his foot; it sliced right through the side and sole of a heavy army boot and half an inch into the side of my foot!

Sometimes this troper just crashes into cars. And other things. I always ask to make sure the item I crashed into is okay first, because I can heal; a car can't.

On a narrow street with cars parked on both sides, i had to bike behind a car. Cue me slamming into it's boot door when it stopped suddenly. A second time, the car was stationary and i was the one who stopped suddenly because I'd absentmindedly biked into the back of it at full speed.