We have found that stopping our eTron on a downhill grade, you must be careful about how you shut off and restart the car. If you allow the transmission to hold the car in Park for even a second, instead of the parking brakes, you are in for a nasty restart. Because when you try to take the car out of Park again, you will get a nasty clunk from the transmission. A clunk that cannot be good for the car. We've found you need to stand on the brakes once you've come to rest of the hill. Remain on the brakes will you move the trans to Park then set the Parking brake. Then you can get off the brakes. When you are ready to leave next, again get on the brakes. Start the car, pull the shifter out of Park and free the parking brake. Should be smooth.