Full Auto

The final race in this series was the only one i had trouble with in the entire game, I suggest using the Outlaw with Tactical weapon set these are the most suitable for this race, once your in front the smoke will help you stay there

This one is kind of hard, but the best way to get it is to not rush out to the lead right away, since you'll have seven cars on your tail filling you with bullets. Since these races are multi-lap, hang near the back of the pack for the first lap, softening up the cars in front of you with machine gun bullets or rockets. Try not to destroy them though, since they'll respawn behind you good as new; remember, we want as few cars behind us as possible at this point.

Don't worry about the cars in front getting an insurmountable lead: the game uses rubber-band AI, so enemies will always be around you.

On the last lap, start destroying the guys ahead of you and start moving up towards first place. Use grenades as your rear weapon to keep enemy vehicles off you; shake the back end of the car around to throw the grenades out over as wide an area as possible.

Use boost whenever an enemy is too close behind, but be sure to save some for the final run to the finish line since your car probably won't be in very good shape by this time.

While your mileage may vary, I got the best results using a x1 forward weapon coupled with x3 grenades for the rear.