According to http://www.ign.com/wikis/gcn-cheats/Cars_Cheats , IMSPEED is nonexistent on GameCube.
But, the VROOOOM code is said to give a fast start on GameCube, which is what IMSPEED does on PlayStation 2. CONC3PT supposedly gives infinite boost, which is what VROOOOM does on PlayStation 2.
I would assume that VROOOOM would be the official substitution for IMSPEED on the GameCube for the Any% Cheats category, but I would ask the moderators first to make sure.
Effective July 1st, all Glitchless categories for Cars will officially be removed from the leaderboards. The rules were deemed too subjective and arbitrary for fair rulings, clarity, and good competition, and compromises would either not solve these issues or create a redundant or inferior category.
