To ease the painful wait for Dirt 4 to come out i have made Solberg and Kristoffersson's livery for this years PSRX Volkswagen Sweden. Have fun!
http://www.psrxvw.com/
http://www.psrxvw.com/
If you export the 3D files from the game with a software like 3DSimED, you can import obj files to photoshop and paint on the texture layers. Then you can instantly watch you changes in the 3D php file.