Xtreme Racing:

        On the 1st selection screen type any of the following:

            "SHEEPY SHEEPY"________________For a sheep as a vehicle.
            "TURBO NUTTER BASTARD"_______________________________????
            "IDKFA"_________________________________For auto qualify.
                (and access to 3 bonus track in single track mode)

        HINTS:

        Grassland 1 has a short cut - where you have the blocks in the
        middle of the road.  Go just past there and you can drive through a
        tree.