Mario Kart Wii/Leaf Cup

DS Desert Hills
This track is exactly the same as the DS version. Pokeys can be everywhere, and the sun can shoot out fire balls.

GBA Bowser Castle 3
This track is a basic lava pit with Thwomps in some possibly annoying places, so chuck some bananas and fake item boxes around these and you can seriously slow people down. There is one section where you can perform loads of tricks in a row so take advantage over this. You can also do a trick where there is a speed boost powered ramp, although it is possible to smash into Thwomps in mid-air.

N64 DK's Jungle Parkway
Nothing much. Use mushrooms up the hill in the tunnel before the finish line.

GCN Mario Circuit
Evil chain-chomp dead ahead! He will eat your head off! Don't run into them. Get a mushroom and zoom in the grass by the chain chomp. Be careful of the angry mob of goombas and the bumpy hills.