IMPORT TUNER CHALLENGE

The above solution is correct. I will just reiterate some main points and add some :)

Very easily boostable with a friend. It must be a ranked match for the achievements to unlock (even though the description does not state it). You and your friend simply take turns winning.

You'll have it after an hour and a half to two hours (if alternating wins).

For each race, the host will have to recreate the match. Make sure to reduce the match point to one to maximize the wins.

You can also help to speed up the wins when it is your turn to lose by reversing into the opposite direction while side swiping the walls.

The longest part of this is setting up the race, finding the race and waiting during the loading screens. The races only took maybe ten to fifteen seconds.

This can be done with a friend. The matches have to be ranked. There still are a small amount of people still playing this game,but it isnt to hard to get matched up. Make sure that the loser grinds the wall to make his or her meter drop faster. And all the winner has to do is hit the nitrous.