I built a trailer for my son's dump truck and couldn't wait any longer to give it to him. It has fold down ramps, 4 tie down points, 2 axles with duals, and a jack which I need to weld a handle on.
Oh, you make me miss the days when my boys were that size. That is a great present that he will someday give his son / daughter.
One suggestion since your son is so young. You might want to put a piece of slip on rubber molding all around the top lip, so when he falls on it it won't cut him. You can pull it off when he gets a llittle bigger.
Great suggestion! He has a bruise on his back from falling on it after 10 minutes of ownership. I will install some of the strips like you can put on the edge of an automobile door tomorrow.
I'd like to build a heavy duty bulldozer to haul on it someday. He got a plastic dozer for christmas that looks cool but won't be pushing anything except legos.