If you beat all the cups in 50 - Mario Kart Double Dash
3 Dec 2004, ID#2858
If you beat all the cups in 50cc through 150cc you will recieve the Mirrior Course.
You will recieve these if you beat the Mushroom, Flower, Star, Special, All Cup Tour Cups:
(I don't know what the name was but it is a battle mode stage)
Petey Piranah & King Boo With Piranah Pipes
All Cup Tour: