(only at episode 21 at the time of typing this) By now I'm convinced Space Dandy takes place in the same universe as Cowboy Bebop. Same currency, "the fridge monster" from the famous spooky CB episode "Toys in the Attic" appeared in episode 8, and I swear I caught another reference somewhere but can't remember it right now.

Though of course "alternate dimensions" are a factor in Space Dandy, so that's another theory.