For 30,000 bonus points, hit the afterburners as you enter the canyon on level 4. For another 65,000 hit the afterburners again while you're in the canyons. A good spot to try the second bonus is right before you enter the second set of canyons.

You'll be greased lightning with this set of passwords.

Level  Password
1      AAAA
2      PLAN
3      ALFA
4      BELL
5      NINE
6      LOCK
7      HAND
8      FLEA
9      LIFE