On my 27" Full HD monitor I have a low pixel density and I have to set the anti-alias filter multisample to 8x to eliminate the annoying jaggies on oblique and curved lines. If you have a better monitor or a less demanding eye you can lower the anti-aliasing and evaluate the trade-off between graphic rendering and performance gain.

The same goes for the anisotropic filter, which improves the quality of distant objects, making its shapes well defined and eliminating the annoying blurring.

Modulate the anti-alias and anisotropic filters values ​​if you have to do so to get an acceptable frame rate, but I suggest you give up everything else (shadows, reflections, sky, motion blur) and keep these two filters at the highest possible level.
_ _ _ _ _ _ _ _ _

custom

NO

multisample 8x
cinematic NO (blurry)
FXAA NO (blurry and laggy)

anisotropic filter ULTRA
texture dimension ULTRA

detail level ULTRA
Experimental LOD NO
static detail (it work with activated experimental LOD only) so NO
vehicle detail ULTRA

SET ALL TO MINIMUM (you don't notice difference in game)
global illumination MEDIUM
ambient occlusion OFF
volumetrics LOW

SET ALL TO MINIMUM (you see big difference in showroom but you get almost the same graphic result during a race)
enviroment reflexion LOW
car reflexion LOW

SET ALL TO MINIMUM (you don't notice difference in game)
shadows VERY LOW
experimental sim shadows OFF
sim shadows LOW
screen space shadows OFF

(you don't see differences in the sky and grass while racing, the first level for grass is enough)
grass density LOW (if you set OFF all the grass disappears)
Cloud density LOW (the minimum is good enough, I see the same sky)

(leave default)
- post processing presets DEFAULT
exposure 0.0
fidelity fx contrast 0%
veil type SOFT
depth of field ULTRA

SET ALL TO MINIMUM (you don't notice difference in game)
motion blur quality OFF
motion blur strength 0%
motion blur central quality 0%

<Quick troubleshooting> mirrors mode SINGLE
mirrors resolution HIGH
mirrors view distance ULTRA
optimized rendering ON
mirrors capture mod FIXED

<Quick troubleshooting> if you can't set virtual mirror from UI settings because it is deactivated, then come back in video settings, set mirrors mode ALLS and come back to UI settings to set virtual mirror ON. Finally you can set "SINGLE" mirrors mode again on Video settings without losing virtual mirror activation in UI settings.

During a race I'm able to clearly see a distant opponent's car in front of me on a long straight with its decently defined edges.