You can't, because that track isn't in Mario Kart DS. It is, however, in Mario Kart 7, which was the first game to have retro Rainbow Road tracks.
They aren't
Super Mario Kart (スーパーマリオカートHelp:Installing_Japanese_character_sets)Answers.comis a Kart_racingRacing_gamedeveloped by Nintendo_Entertainment_Analysis_and_Developmentfor the Super_Nintendo_Entertainment_System(SNES).()
Mario Kart did not come before Mario World. Mario World and Mario Kart were for the SNES. Mario World came out 1991 and Mario Kart was released in 1992, a year after.
Its not Super Mario Galaxy.The course is Rainbow Road.
a race track on mario kart wii
They are the bottom row of cups in the track selection. They were tracks from past Mario Kart games. They are labeled with 2-4 letter abbreviations like.... SNES - Super Nintendo Entertainment System N64 - Nintendo 64 GCN - Nintendo Gamecube DS - Nintendo DS GBA - Gameboy Advance
Get a rainbow star item.
There are currently 8 Mario Kart games:Super Mario Kart (SNES)Mario Kart 64 (N64)Mario Kart Double Dash (GC)Mario Kart Wii (Wii)Mario Kart DS (DS)Mario Kart Arcade GP (Arcade)Mario Kart Arcade GP 2 (Arcade) (Japan only)Mario Kart Super Circuit (GBA)
The shortest time on Mario kart wii: Allowing Glitch Shortcuts: 19 sec Grumble Volcano Dissalwing Glitches: 54 sec SNES Ghost Valley 2
Rainbow Road includes some Mario Galaxy aspects, such as star bits. Also if you have a save file on your Wii with Super Mario Galaxy and Mario Kart Wii you can get a character.
time 1:23 on rainbow road
crash into the rainbow boxes on the road.