ATV:
Hold R1 and hit Up, Right, Down, Up, Right, Down at the main menu and then
select a snowmobile.

Go-Cart:
Hold R1 and press Right, Right, Left, Left, Right, Right at the main menu. Select
a snowmobile and start the race.

Demo mode:
Hold R1 and press Up, Up, Up, Down, Down, Down at the main menu.

Extra snowmobiles and tracks:
Complete the 500cc class to get the hill climb, extra snowmobiles and tracks.