.dds (main skin) .veh (vehicle definition file) Cockpit.dds (cockpit dashboard) Driver.dds (driver suit) Helmet.dds (driver helmet) Window.dds (EXTERIOR windows) Windshield.dds (INTERIOR windows - only used in cockpit view). Body, glass, cockpit - DXT5 Driver suit, helmet - DXT1 The PSDs have appropriate generic alpha layers built in, just save to dds when you've finished painting :) If you put a logo on the glass/visor textures it will also have to be added to the alpha layer of the glass in order for it to be opaque ingame.