Download song at:

Before they reach Rainbow Road, the Mane 6 must race in Bowser's Castle, which is infested with King Sombra's dark crystals, Thwomps, fire geysers, and they must get through both Mecha Bowser and Mecha King Sombra. Also there are Special Cup's elite Mario Kart and PonyKart racers that have entered the grand prix and they are...

Metal Mario
Honey Queen
Millennium Star (Mario Party 3)
Mr. L (Paper Mario Series)

King Sombra
Delta Brony
Eurobeat Brony
Vinyl Scratch
Super Rainbow Dash
Surprise Pinkie Pie

For Delta Brony, when he gets behind a racer, he gains Triple Mushrooms for every Slipstream. For Eurobeat Brony, when he is in 3nd or below, he gets either a Mushroom, Golden Mushroom, or a Power Star.

BPM: 155
You can make a simfile.

MLP by Hasbro
Mario Kart Wii by Nintendooo