Are the Mario Kart Wii Ultimate Glitch Rumours true?

Apparently there is some random bugs with Mario Kart Wii. One where you can jump and carry on along the wall back to the finish? Lots of people on YouTube.com are really buzzing about these so-called Ultimate Glitches. There's one that I watched about the "Ultimate Mushroom Gorge Trick" Where the person just jumps and carries on and on and back to the start :S I know they are probably fake but everyone on YouTube seems to want to know whether these are possible!