I've been looking at the materials of the vehicles and narrowed it down to three main materials; Wood, Metallic and Rubber.

These are what I have been looking at using google to get some basic research down of materials. I then started to try and replicate them for myself. 

I need to practice the sphere styled textures to show some more depth of each of the textures. This mood-board is to help plan how the textures are going to work and where they are going to be placed.