This barely qualifies as a guide. Really just some quick information that transformed my VR experience in this game. Hopefully you can benefit from it too.

I'm running a Valve Index, but I'd say its worth a try with other headsets too.

I've applied both of these tweaks together and they produce a wonderful image.

Navigate to \Documents\Project CARS 2 and open graphicsconfigopenvrdx11.xml in your favourite text editor.

Change the following values to match:
<prop name="SharpeningStrength" sharpeningstrength="0.700000" />
<prop name="SharpeningClamp" sharpeningclamp="0.050000" />
<prop name="OffsetBias" offsetbias="1.000000" />

Grab this https://github.com/fholger/reshade/releases/tag/openvr_alpha2 and install it to steamapps\common\Project CARS 2

The default values work well for me, but if you have a different headset you may wish to adjust things like the saturation value back down to 1.0 depending on your tastes. To do that load up reshadepreset.ini from your game folder in a text editor.