The car could launch a quadcopter to handle the driveway-to-door part. The car wouldn't even need to stop. By the time it's turned itself around, the quadcopter

The car could launch a quadcopter to handle the driveway-to-door part. The car wouldn't even need to stop. By the time it's turned itself around, the quadcopter would have probably made the delivery. Security of the package and picking an appropriate drop point seem the most difficult parts to me.