Didn't work for me, but it was worth a try I guess. Thanks anyway, maybe I'm doing something dumb? but I did change the value in the player.json. Then I launched rF2 again, and changed cars, the mirrors were all over the place like beforeIn the graphics section of the player json file, set this line to 0
"Moving Rearview#":"Whether mirrors respond to head movement in cockpit (0=none, 1=position-only, 2=FOV-only, 3=both) - add 4 if you want to IGNORE head-tracking movement",
With this set to 0 setting there should never be a need to adjust the mirrors again for any car. I really think this should be the default setting.