This achievement can be gained whilst working towards the 'From DiRT to Glory' achievement.
I gained the achievement after finishing first place in all four seasons. If you don't have the achievement by then, you will be able to get it whilst working on the six remaining world tour events.
This achievement is very easy to do whilst the opponents difficulty is set to 1 and all driving assists are enabled. Difficulty and driving assists can be set before the start of a race.
You earn extra XP for completing race objectives and for any unused flashbacks.
Driver Rep can also be earned online playing in any multiplayer mode.