El T, if the city has an ordinance about it and you want to be a dick, then call and complain and maybe they'll ticket him. And then you'll have an enemy for life if they find out it was you that called. If there's no ordinance, just forget about it, cause it'll just breed bad relations with the neighbor and you can't do squat about it anyway.
FWIW I live in a stupid yuppie suburb (working on getting out) and I'd *love* to be able to park in the yard. 5 people with 5 cars makes my driveway seem really slim, but I dutifully re-arrange the cars every night so that they won't ticket me for parking on grass or parking in the street overnight. It's so nice that the yuppies with the 4500 sqft houses with 4 car garages get to make the ordinances for my small, older neighborhood.