Hi Turtwig I made a big Kart hack.USA version. change acf8 to AD18 to change codes to European code.
Large Kart:
6217acf8 00000000
b217acf8 00000000
000000bc 00002000
000000c0 00002000
000000c4 00002000
d2000000 00000000
Use the star with that to make you feel like mega mushroom on wii...