Trailers made from truck beds
Hehe, I had one made out of a 90 Chevy P/U that I picked up for free, (totalled, but the bed was mint). On the tailgate it said, "Chevrolet, the best made trailer in America." We used to put this thing on job sites to load with garbage. It would usually get the Chevy guys fired up pretty good.
The kid I gave it to took that off the gate and put his own saying on it. Now it says, Chevy, professional grade trailers. It's worth a laugh every time I see it.