I've seen some fairly sturdy looking 4x4 or 6x6 lumber and plywood extensions. They braced the front of the 4x4's from the floor up to the underside of the bed rail at each of the four corners to keep it from flopping and had it bolted through the stake holes so it couldn't slide out. Put trusses throughout for strength. Placed lag bolts with eyehooks and washers to tie everything down and ta-da! they could haul an extra quad to the track without too much fuss. This was on an F-150 though so really now that I've written all this I realized that you'd have close to/over 1,000lbs in the bed of a ranger with prolly 70"/400lbs(raptor?) hanging behind the bumper
Most likely bottom it out anyway no matter how you got both machines mounted onto/into/through your truck
So most likely a trailers gotta happen. Also too, I don't know if I'd trust my baby to lumber hanging out over the asphalt on the open road but hey it worked for them I saw them year after year at a local MX track. Good Luck!