Hi,
I was still struggling with this achievement. The suggested races didn't really help me because I always ended up 3rd or 2nd.
I found that the GP Circuit in Yas Marina was easier to finish since the A.I. always messed up the turns.
Go to:
Custom events
Tier 2 vehicles
Location: Yas Marina
Track: GP Circuit
Car: Dodge Challenger (but any other car should do as well)
If you need more help refer to the video below:
(Video credit: Lightsp33d1987)
Hope this helps you guys
Any improvements? Please let me know in the comments below !