DiRT 4
48 Achievements
1,000
60-80h
Rubbing, son, is racing
Won the FIA World Rallycross Championship
40
3.07%
How to unlock the Rubbing, son, is racing achievement in DiRT 4 - Definitive Guide
All of the events contain 6 races, 4 of them to qualify for the semi-final. You only need to win two of them, then you can retire after the beginning of the other two ones, the points will definitely be enough to qualify (normally around place 3-8).
But don't forget to drive all of the four qualification-races in one event to get the "First on the GRID" achievement.
To unlock the Rallycross events, you will first need to complete 10 different events in the other categories. Once it's done you will earn the license that will allow you to play in Rallycross. Complete the available events to unlock other events, until you're able to play the last event which will be the FIA World Rallycross Championship. Once a new set of events is unlocked, you don't have to beat the remaining events in the previous one if you don't want to. While progressing through your career to unlock the last event, you will also earn the International Off-Road C-3 and C-1 licenses which will give you their respective trophies.
The FIA World Rallycross Championship has 5 events and every event consists of 4 qualifying races, a semi-final and a final. You don't have to win all the qualifying races, but you do need to reach and win the final to get the trophy.