List of Mario Kart: Double Dash!! pre-release and unused content

These are the beta elements for Mario Kart: Double Dash!!

Early iteration
The models of the characters are from Super Smash Bros Melee, and Mario and Luigi are seen in this trailer of a very early build of the game, driving separately, each in a simple, blue kart. It was originally called Mario Kart for GameCube, and it is likely that this early build of Mario Kart: Double Dash!! was completely scrapped and redone for the final game, as it looks nothing like it.

Mid-development builds
Several screenshots released during the development of the actual Double Dash build shows different textures, tracks, speedometer HUD, and racer pictures.

Unused data
Pressing         at the end of a trial mode race (where save ghost and replay are) will bring up a series of numbers and letters, presumably for debugging purpose. This doesn't do anything, but it is interesting to see that Nintendo forgot to take it out of the game.