Probably some obvious video card setting but I don't know what it is. AI have big gray vertical 'pie plate' spoilers on the rear. If I'm close to them they reflect my cockpit.
The infamous "heat haze bug." You are probably using an advanced AA configuration to get rF2 to look good and this is the reward. I have some strange combo where they only show-up in the rearview mirror. You can get rid of them easily enough by using standard AA settings, at the expense of more flickering and more jaggies on the screen. No real solution to this from ISI after 2 + years.
With the FSR mod it's clearly visible as well. While I've gotten used to it, it would be nice to know how to get rid of it. I use standard AA settings already. I'd describe it like a big round-ish/oval-ish orb.
In your player json file (set to 0 to disable effect) "Heat FX Fade Speed":0, "Heat FX Fade Speed#":"Speed at which exhaust heat effects reduce by half (0 to completely disable)",
Enable HDR would be the best way to sort it out. If you CANNOT run HDR, then you can disable as in the post above.
Turning it off doesn't fix it, obviously. You no longer have the heat haze effect, which is nice if set lower than the default. There are cars that it works beautifully with, like the new Palatov D4. But most where it is coming from rear exhaust have the annoying "circles" (Palatov exhaust is on the top to the right of the driver). Maybe it is a car-by-car fix?
Wrong Nvidia Inspector settings trump all Marc whether you edit json or not. AMD don't know don't care
Disabling Heat FX Fade Speed worked just fine. Guess I'll have to live w/o the heat haze. Low on my list of life's problems.