The funiest thing I saw wasn't truly a mod, maybe it was just a poor attempt to replace a missing fender on a car. This was several years ago in Palmdale CA. It was a hideous green Dodge Dart and instead of having a driver's side fender, the guy put a piece of ugly green shag carpet to take its place. It was heading in the other direction but he was going slow enough for me to get a good look.
