When you start the mission and are going to get the car, turn to your right instead of left into the door at the end of the catwalk Turn left there and you will find a black motorbike. Also when the level begins, instead of heading left on the catwalk to get the Cayenne, turn right. You will find a garage with a motorbike. This bike takes no damage from crashes, and the route is easier with less enemies along the way.