Ben 10 Galactic Racing
50 Achievements
1,000
12-15h
Xbox 360
Driverus Primus
Beat the Track Best time in a Time Trial on any Primus track.
15
How to unlock the Driverus Primus achievement in Ben 10 Galactic Racing - Definitive Guide
DaShAg 
TrueAchievements
TrueAchievements
Any of these tracks will work:
Codon Climb
Gavlan Gorge
Jungle Run
Azmuth's Forge
Codon Caldera
I would recommend going for the Azmuth's Forge track though since it unlocks a kart needed for another achievement: 
The Kart Collector achievement in Ben 10 Galactic Racing worth 61 pointsUnlock all of the karts in the game.
Codon Climb
Gavlan Gorge
Jungle Run
Azmuth's Forge
Codon Caldera
I would recommend going for the Azmuth's Forge track though since it unlocks a kart needed for another achievement:
The Kart Collector achievement in Ben 10 Galactic Racing worth 61 pointsUnlock all of the karts in the game. 