I've had this in the demo also but didn't pay attention since I'm thinking it's only demo but when I went ahead and bought the game it's still there. The adjustments I made was in nvidia control panel and nvidia inspector for graphics which I did one at a time till I get what I wanted. In-game mostly on full with 80 -170 fps.You've always had that or it's appeared after you tweaked settings, I've never seen one of those before?
I'm getting ready for work now, will check on this when I get back. Thanks.It's a Heat Haze issue, see here and post #2:
http://isiforums.net/f/showthread.php/27148-Graphic-balls
http://www.racedepartment.com/threads/rf2-graphic-bugs-things-to-check-first.106607/The adjustments I made was in nvidia control panel and nvidia inspector
I read about this that's why I deleted and created a new .json file but dit not delete the logs in usedata. I will check on this again. Thanks.