Unfortunately Kylotonn have now changed the way PKG files are extracted in WRC 10 shipping version.
This blocks many aspects of the modifying the game, Physics, Tyres, UI, Dashboards, In game cameras, etc.
They released the WRC 10 Steamfest demo that uses the the same original method as in WRC 7/8/9.
If I get some time I might be able to reverse engineer the demo exe and the first shipping exe and then compare the two to see what they changed
EDIT: WRC 10 can now be modified
Yesterday I began working on shader mods for WRC 10 to enhance world lighting, headlights, brake lights, rain effects, windscreen reflections/dirt/damage/rain, dust particle effects, screen space reflections, motion blur, depth of field, god rays, lens flare, sun flares etc. Most of my WRC 9 shader mods will come to WRC 10.
WRC 9 Mods v2.0 is 99.9% completed, I will add Ced's latest files to it once released.