1. development branch of ARMA 3
2. open the Editor and create an empty Offroad and an armed player
3. preview the mission
4. get in the front passenger position of the back of the Offroad
5. choose "turn out" (left ctrl-e)
6. now "turn in" (left ctrl-q) and immediately "turn out" again
7. congratulations, you are now sitting down and facing to the front