To drive up to someone's house or apartment and proceed to honk the horn until they come out, rather than going to all the trouble of exiting the vehicle and going to the door.
Cletus across the street had a friend that would ring the Kentucky doorbell each morning at 5:00 am. I say "had" because me and my tire iron had a little chat with him.
Guidos, frequently too self important to actually get out of their cars, or even call someone when in front of the house, beep their horns to let the person inside know they have arrived. Perhaps they are under the assumption that everyone else on the block is deaf, or wants a good look at their all around dark tinted windows on a white BMW.