So I finally got around to testing my theory today that it was my faulty PSU causing GR:FS to crash my system after about 20min of play. Turns out it wasn't

The game freezes for a couple of seconds, during which the restart button doesn't even work, then the PC switches off completely and boots up again by itself

I am quite clueless now as to what could be causing it. Has anybody else had this problem???

I REALLY don't want to delete and re-download the game