This is the second of three Online leveling achievements, the others being at ranks 10 and 30.
Sadly the game is more or less dead online, so your only real option is to boost. Thankfully there is a relatively efficient boosting method which I will illustrate below.
You will need:
- 8 players (the exp drops off quickly with any less than this)
- the "VIP Pass" (which is the reason these achievements are "partially discontinued/unobtainable", because without the pass you can't get them, and the pass is only available on the Xbox One store, not the 360 one. I believe the pass is also obtainable via code redemption, but there are not many unused codes left for what is now a 9 year old game).
First off, have the host set up a Private "Hoonigan Solo" lobby, and invite everyone. Then people need to veto all "Trick Rush" events - resulting in only "Head 2 Head" events being selected, and also veto the "Los Angeles Stadium Gauntlet" track. The result should be that you get Head 2 Head events on either Yokohama or San Francisco.
For Yokohama:
All players Drift on the first corner then Smash straight after, then head directly to the finish without getting any other objectives. (You will all go through another Smash but it won't count).
For San Francisco:
All players go through the first Smash, then head directly to the finish without getting any other objectives.
If done correctly, everyone will tie and get the same EXP as if they had won. You should each get 1000 xp every 3 minutes or so.
Level 20 requires 87000expm, so you will need 87 bosted events to get there. At 5 minutes per event including loading screens the total boost should take about 7 hours 30 minutes.
Level 30 requires 250000exp, so you will need 250 boosted events to get there, which should take about 20 hours.
The levels take progressively longer, apparently level 25 is about half way to 30 in terms of exp.
(Sadly I don't know the exp requirement for level 10 (please let me know below if you know).
Best of luck if you're going for the completion! Check out gaming sessions for the game here:
DiRT Showdown Sessions