The plate that joined them went the way of Ol' Yeller when the caddies switched to rollerblade wheels. The wheels wouldn't stay in with the plate attached. I believe Grit Guard got away from those wheels though.
I like my bucket caddies. Wouldn't want to wash without them because I'd have to lug 2 buckets around the vehicle. However, once you have 2 of them you'll never need to buy them again in all reality. One of those things you'd keep a low supply of.