I'm a little confused as to the question, mostly because I don't understand why it would be an issue for a car to use a driveway you share just to access their own garage. It's your neighbour's son, but how else would he use their garage (with their permission, I assume) without using the driveway you share? With that said, property law isn't our area of expertise. It's my understanding that if someone who owns part of the shared driveway damages it and doesn't contribute towards repairs or blocks the driveway then that's an issue. However, the driveway is - in this instance - an easement, meaning that it's the right of one landowner to make use of another piece of land for the benefit of his own land. For example, if you buy a house with a shared driveway, part of the area you drive over to access your house may belong to a neighbour. Your property paperwork should explain how the driveway is shared.