[Anton Vuksanovic]

how you down car resolution?

You can do it in many programs for pictures view or pictures processing. For example, XnView do work for me.
Just go to folder where is your steam is instaled and then: ...steam\steamapps\common\assettocorsa\content\cars.
There you can find all cars folders that you have in game. Open one you wish to "fix", and then inside that folder open folder named skins. There you can find all versions of the selected car ( if there versions ). Inside each one you will find textures in .dds extension. Open .dds files with XnView, then resize their resolution ( I set it at 50% of original) then save it and that is all.