The Audi A5 project sketches are really great, super simple but precise with a very refined color technique. The cool grey scale used to render them looks very metallic, good detail work on window reflections and side body sections.
The perspective is well set and the big wheels well proportioned in size compared to the overall car proportions, the cutlines design very well the real sections of the car, they help the sketch to feel like if it were in 3D.
Check up the rest of the fotogalley clicking: Audi A5 sketches