What Would You Do?

My yard and my neighbor's yard both have retaining walls, so the yards are higher than the driveways. Every time my neighbor mows his grass, he lets the clippings blow up the sides of whatever vehicles happen to be parked in the driveway. He's done it to G several times. G said he's said something to Bruce, who blew it off. He said it wasn't hurting anything and would rinse right off (it does not). He said he would let us know before he mowed in the future. He's never made any attempt to do that. He did it to me once...I promptly went out with paper towels and spray cleaner...but since my Tahoe is dark green, the grass cooked onto it right away. I really had to scrape and scrub to get it off. He apologized, and I asked him why he couldn't simply turn the mower the other way. He mumbled something about there being a tree close by. I fail to see his "logic".

So, this morning I heard mowing, looked out, and sure enough, he had mowed up the side of G's Jeep again. G took his motorcycle to work today...I wonder if Bruce wasn't waiting for him to do so. So, now what do I do? Do I go confront him, or just let some of the dog crap we're scooping out of our yard accidentally make it over the fence into his yard? I really hate to be vengeful and start a warring neighbors thing. That could get ugly fast. We have already had problems with him-he decided to grade his entire back yard, without a permit. He brought in a Bobcat and went to town. He actully looked like he knew what he was doing, and took precautions and so forth. However, he climbed up on the temporary retaining wall, and our yard collapsed 12 feet down into his. Needless to say, we were less than pleased. In fact, I was extremely pissed. He did build us a new retaining wall, as promised, and it's perfect--industrial strength. But still. And if we'd have reported him, he'd have been fined heavily.

So I don't know what to do. Any ideas? Do I just go over and say, Look, this is not cool. You wouldn't do that to the neighbors on the other side, so don't do it to us. I get the feeling he just sees us as kids, and he can be manipulative as he pleases.

What would you do?