You can't do so at all. R.O.B. is only available in the Mario Kart series in Mario Kart DS.
Rob is not in Mario Kart Wii.
ROB is not in Mario Kart Wii, he is only in Mario Kart DS.
You can not get ROB in Mario kart wii, only in the DS version of the game.
there is no goomba to unlock in Mario kart wii
Rob isn't a character on Mario Kart Wii. He's only on Mario Kart DS.
R.O.B. didn't appear in Mario Kart Wii, but he did in Mario Kart DS. He was an accessory for the NES, which acted as another player in Gyromite and Stack-Up.
no but he his in Mario kart DS
You can't unlock Pauline in Mario Kart Wii,he isn't in that game.
Wiggler is not unlockable in Mario Kart Wii.
Rob is not available on wii only on ds
If you need to unlock her in Mario kart wii here is the answer: Win the 150cc Special Cup. If you need to unlock her in Mario Kart 7 here is the answer: Win the 150cc Mushroom Cup. Source: I beat Mario Kart Wii, and I unlock Daisy in Mario Kart 7.
There is no 300cc cup on Mario Kart Wii.