Mario Kart Double Dash

(M) (Datel)
ANZT-AP2Y-0JYEY
KG16-PZFM-223FE

Stop/Start Lap Counter (L+R+D-pad Left/Right) (donny2112)
AZJM-Z81K-65ZX5
1XG9-ZUXY-5WR6Z
X38B-XT8T-4BKKT
QFWB-0X0D-2A823
2F2N-ZCM8-4RGNQ

Notes

Don't use this on the first lap! I also wouldn't recommend using it on the last lap, though I don't know of specific problems with it.

The way this works is that if you stop the counter, when you cross the line, your laps won't increase. This will probably give you a blast on Baby Park. Once you restart the counter, though, all those laps will add up to one big lap time, so don't use the code if you want to win the race.