Pictures of so-called "redneck limos" are very popular on the internet. There's quite a few of them to be found, and here's a selection of the ones that seem to be most frequently posted on blogs.

Are they real or fake? My hunch is that most of them are probably real. After all, there's no reason vehicles like this couldn't be built, and there are companies that specialize in building things like this. One such company is SuperDuty Headquarters, whose sign can be seen in the rear window of the truck in the first picture below (although I can't find any pictures of that truck on their website).

The picture I'm most skeptical of is the one of the white stretch limo with the trailer attached to the back. That trailer could easily have been photoshopped on.