i got some just like that (except made of plastic) at the day at the docks fishing show. they were $10.00 each, and they're actually really durable. instead of bolting on, they attach to a tube with a cylinder shaped velcro strap/clamp device. also, they extend downwards to hold a tall-boy, and they have neoprene lining to hold your beverage tight. I bought them for my beach cruisers, to carry beverages on the boardwalk. There was a kid next to me buying a couple for his 50's to cary beverages on gecko rd. you just un-velcro it from the bike and mount it on the buggy or boat or whatever - it's cool.
actually a lot of people buy them, im not trying to throw a sales pitch out there, but...we do have them in a polycarbonate model, they run about $25. and that clip from the 2000, the builder/designer of the BCS ran the 2000 in a baja challenge car.