Due to ongoing internet issues (which are now fixed) this optional HD textures pack got delayed.
This texture pack adds 4K vehicle textures for the absolute best possible visuals. This pack is NOT recommended if you are running AHD on the original X-Ray engine - you will likely hit the executable memory limit (about 3.5GB) and run into out of memory CTDs
To install this pack just extract the Gamedata folder to the main stalker directory and overwrite when prompted.