The Jeep Wrangler is the third car you get in the game, it is also unmissable story wise.
To get this achievement, first, make sure you have acquired the Toyota Supra '98, the second car. You will unlock a race which is around 4 miles, win it, and you will be introduced to another race
For some odd reason, on the 360, you get no nitro/turbo for this mission, on the Xbox One you do though, so this means that you should do an absolute perfect run on this raceIn this race, you must beat an attack helicopter in an armoured Jeep.
This may seem extremely unfair, and although it is, you will win if you can just keep your speed at all times.
Don't skip corners, as helpful as this seems, most of the corners in this map are just turns, which will definitely lead to a crash. Just follow the arrow almost directly and you'll be fine.
Use rewind if necessary, please remember it is there.
Turn off the assisting brake, as it will brake you at something unnecessary e.g Near the end of the race slope
Also, due to the amount of times you go offroad in this mission, you may obtain this achievement just by trying to beat the race: