Oh, and Mew is the Best, here are the unlockables...
50CC
Mushroom Cup: Green Fire (Kart)
Flower Cup: Bloom Coach (Kart)
Star Cup: Para Wing (Kart)
Special Cup: Bullet Blaster (Kart)
All Cup Tour: Nothing
100CC
Mushroom Cup: Rattle Buggy (Kart)
Flower Cup: Waluigi Race (Kart)
Star Cup: Special Cup
Special Cup: Toad & Toadette (Characters), Toad Kart (Kart)
All Cup Tour: Nothing
150CC
Mushroom Cup: Luigi's Mansion (Battle Mode Stage)
Flower Cup: Turbo Birdo (Kart)
Star Cup: Barrel Train (Kart)
Special Cup: All Cup Tour (Grand Prix Mode)
All Cup Tour: Mirror Mode (Engine Options)
Mirror Mode
Mushroom Cup: Toadette Kart (Kart)
Flower Cup: Tilt-A-Kart (Battle Mode Stage)
Star Cup: Petey Piranha & King Boo (Characters), Piranha Pipes (Kart)
Special Cup: Boo Pipes (Kart)
All Cup Tour: Parade Kart (Kart)
I moderate a lot of Pokemon forums, 2 to be exact, I love them, but I love Harry Potter games even more!