Crash Nitro Kart (Adventure Mode) - Barin CNK/Crystal Challenges

Meteor Gorge has one out of the way letter but that's it, Barin Ruins I'd be screwed except I got a lucky boost powerup, and Deep Sea Driving in general ain't too bad, as the letters are on my usual route anyway.
Frozen Frenzy requires tight weaving through the cave section, and nice use of powerups. Not the biggest of worries though.