The Ultimate Experience Achievement
The Ultimate Experience75
Complete All Sprint Driver Challenge Events.This one will take some time, as there are 77 of these. You'll get performance points after everytime you beat a challenge, just use those on your car and that should help you out some. I have not gotten this achievement, so I don't know how long it will take, I am working on getting the achievement now. Will edit when I get it, to tell you how long it will take and stuff. But a pretty self-explanatory achievement.