On my last Barker 32 gal. tote, I bought 2 pneumatic tire from Harbor Freight to replace the hard tires.
Too bad I sold it with one of my previous trailers. I bought the same size tote last year and haven't replaced the hard tires yet. Looks like another mod coming up.
This is how I carried it. I made a mount that bolted to the rear bumper.
The mount was made of a piece of metal plate with a section of universal square tubing bolted to it.
The plate was clamped to the bumper using 4" U-blots.
This is how the tote was held in place. The retracable tongue of the tote, was pinned to the universal tubing on the mount.