Artoo bleeped a series of booping whistle noises everytime a pedestrian jumped out in front of the vehicle. How could he be a perfect driver if no one else followed the rules of the road? He found it rather frustrating. And Artoo wasn't an easy droid to frustrate.
"Brreeeooop!" Artoo replied when Anakin instructed him to drive the van into the garage. It took Artoo a moment to realize that the garage door opener was not connected to the ship-- van's memory. Once that was discovered, however, he smoothly drove the car into the garage and parked it. Safely out of sight of other people.
Yeah, that's right. X-Wings. Minivans. You name it, Artoo can drive it!
He disconnected himself and wheeled into the back of the van to look at Threepio, still deactivated on the floor.