The codes are:
1-AAAA
2-PLAN
3-ALFA
4-BELL
5-NINE
6-LOCK
7-HAND
8-FLEA
9-LIFE
You can land upside down on the Courrier Run mission (LOCK).
For bonus points, hit your afterburniners as you enter the canyons on
level BELL. The Gutsy Bonus will give you 30,000 points ("You've got
guts!") When you're in the canyons fire your afterburners for 65,000
points (Lunatic Bonus) "You're crazy!!" The points are added when
you land -- but if you do both, it will only display the Lunatic
Bonus, but you get points for both. (A good place for the second
bonus is right before you enter the second set of canyons).