This truck was sketched using a ballpoint pen and scanned in for photoshopping. 

This is one of a series of sketches I did for a client (which can't be named, sorry). It was created by first sketching on paper, then scanning and adding values in photoshop. The orthographics at the bottom right help the viewer understand what they are looking at and how it could be manufactured.

Wacom Sketch 2

Wacom Sketch 1