In the new Mario Kart for the Wii, I recommend buying the racing wheel. It is definately well worth it, it may not feel like an actual race wheel, but it makes the game a bit more enjoyable when you can actual steer your kart. Plus, if you use the wheel often enough you will receive a Gold Wheel above your name in online play. Below I have mentioned all the requirements for the unlockable items in the game.Unlockable Characters:
- Baby Daisy: 1 Star in all 50cc Cups
- Bowser Jr.: 1 Star in all 100cc Retro Cups
- Dry Bowser: 1 Star in all 150cc Cups
- Funky Kong: Unlock 4 Expert Staff Ghosts in Time Trial mode
- Baby Luigi: Unlock 8 Expert Staff Ghosts in Time Trial mode
- Mii Outfit B: Unlock all 32 Expert Staff Ghosts in Time Trial mode
- Birdo: Play Time Trial mode on 16 courses
- Toadette: Play Time Trial mode on all 32 courses
- King Boo: Win 50cc Star Cup
- Dry Bones: Win 100cc Leaf Cup
- Mii Outfit A: Win 100cc Special Cup
- Daisy: Win 150cc Special Cup
- Diddy Kong: Complete all 50cc Cups in 3rd or better
Unlockable Races:
- Leaf Cup: Win at least 3rd Place in the Banana Cup
- Lightning Cup: Win at least 3rd Place in the Leaf Cup
- Star Cup: Win at least 3rd Place in the Flower Cup
- Special Cup: Win at least 3rd Place in the Star Cup
- Mirror Mode: Win 1st Place in all 150cc Cups
Unlockable Karts:
- Blue Falcon (small): Win Mirror Lightning Cup
- Dragonetti (large): Win 150cc Lightning Cup
- Royal Racer (medium): Win 150cc Leaf Cup
- Piranha Prowler (large): Win 50cc Special Cup
- Turbo Blooper (medium): Win 50cc Leaf Cup
- Rally Romper (small): Unlock 1 Expert Staff Ghost in Time Trial Mode
- Cheep Charger (small): Earn at least 1 Star Rank in all 50cc Retro Grand Prix Cups
Unlockable Bikes:
- Bubble Bike (small): Win Mirror Leaf Cup
- Dolphin Dasher (medium): Win Mirror Star Cup
- Phantom Cycle (large): Win Mirros Special Cup
- Quacker (small): Win 150cc Star Cup
- Rapide (medium): Win 100cc Lightning Cup
- Twinkle Star (large): Win 100cc Star Cup
- Magikruiser (small): Play 8 different courses in Time Trial mode
- Torpedo (large): Unlock 12 Expert Staff Ghosts in Time Trial mode
- Nitrocycle (medium): Earn at least a 1 Star Rank for all 100cc Wii Grand Prix Cups