We have a 6 car driveway for 4 maisonettes. It works out well, because between us, we have 6 cars. I get really annoyed if the neighbours have visitors and they let them park in our established spots, instead of telling them to park on the street, where there is plenty of space to park.
Even more so when you ask them to move their car and you get a "Oh, I'll be gone in 5 minutes" response. Hell no, I don't care. I'm home now, and you're in my space. Move your damn car now.
When I buy a house, it has to have a driveway or a garage. I can't cope with parking wars!