Anyone interested in 3d models and optimization should download from GTA 4/5 vehicle models and look at how they do their texture work. All of the vehicles basically share 90% of their textures and might have a few unique textures just for small details like logos. The models themselves have lots of floating decals, objects just placed inside each other and are relatively low poly.

Kind of neat compared to today's workflow where everything has unique textures and 8 million polygons.