DiRT 4

The fearless preset is not unlocked from the start of the game, in order to unlock it you must first finish the championship (The last event) of one of the game's 4 disciplines and have their respective achievement:
• Rally - Global Superstar in DiRT 4
• Landrush - It's all terrain, dummy in DiRT 4
• Rallycross - Rubbing, son, is racing in DiRT 4
• Historic Rally - Obsolete Models a Specialty in DiRT 4

Once you have the present unlocked select the following from the main menu:
• Events - Freeplay - Rally (Fastest in my opinion)
• Difficulty Settings - Scroll right/left to find 'Fearless' - Scroll to bottom and 'Apply Settings'
• Vehicle - R5 class - Any of the cars will do as they're basically the same specs.
• Move right and 'Add Event' - Location (I used 'Fitzroy') - move right and 'Add Stage' - Length all the way left (Shortest) - Complexity all the way left (Simplest) - generate till you get one that looks mostly straight - Time of day 'Midday' - Weather 'Dry' - Confirm.
• Confirm again.
• Start.

Once you load into the service area simply complete the race (You must complete it!) and the achievement will pop once you begin returning to the garage.

Things to note: Fearless turns off ALL assists, forces cockpit cam, removes the vehicle hud, gives you manual transmission and removes the slowing down after the finish so remember to 1. Use to shift UP and to shift DOWN 2. Take it easy, going too fast could wreck you 3. Slow down at the end.

Finish a race series for me I finished the rallicross tree totally once you finish the big finale championship you will unlock the fearless difficulty setting. Go in to freeplay mode pick a track set difficulty to fearless once you finish and head to the garage screen the achievement as it did for me.