I would think its illegal, because trailers are made to have things placed in/on them, not on top of them hanging off the sides.. If that strap came loose the mower is gonna bounce right off the trailer.. Anyway, the price you got on the trailer isn't bad. I paid $2649 + tax for my 6.6'x16' Ez-Dumper landscape trailer w/ brakes. For some reason trailers are alot more expensive around here.