Check your CMX viewer's dds folder, as it should have VWS_cloth or something...
I think the seat is a mixture of textures starting with VWS_ but I think you should try moving all of them outside of the dds folder, then putting one by one each one back in, and using CMX Viewer to see which one(s) make the seat texture.
[Edit: I've just tried it and I'm absolutely sure it is VWS_cloth1 and VWS_cloth2 that make up the main seat. VWS_cloth3stitch and VWS_cloth2stitch are maybe the edges of the seat and a few places on the dash/interior]