It didn't really "make my day", but it's always amusing to see Karma in action.
One prize moron nearly rear-ended me coming out of the Mixmaster this morning (it's an ugly interchange in Dallas on the 35E). He was violently lane-changing and exceeding anything like common sense. Courtesy doesn't exist in HIS world. A minute and about 10 cars further along I saw a cloud of smoke, so I immediately (softly) applied the brakes, signaled and moved away from it. Yep, same asswipe, with the whole front of his car mangled all to hell, and his car wasn't moving. About 800 feet along I saw a van pulling over with a crunched rear-end, but it was drive-able. People were honking as they drove around Mr. Congeniality.
I felt bad for the person he rear-ended. They didn't need the drama.