Mickeys Speedway USA

[ickle_moi]

ok maybe im just stupid but on mickeys speedway USA i have won all the platinum cups and have all the engine parts on all the 4 singe player contests but i havnt a clue how to access the mirror mode i have searched all the options and game modes
with no luck can anybody tell me how to play mirror mode??
(using pj64 to play)
cheers