My father has been bitten by the HPDE bug, and wants a trailer to tow behind his S2000 to haul a second set of tires, tools, etc. Ideally, he's looking for room for 4 tires and a large-ish toolbox on a small single axle.
I'm up for designing one (probably would post plans on here if I do) but I'd love to get some background information. Searching for "Race Car Tire Trailer" and variations thereof just brings up things to to a track car on, not tow behind a track car.

