Some of the toughest and most demanding storyboard assignments one can work on are the automotive ones. Even though boards are quickly rendered because of deadline considerations, the product must be done fairly accurate. Often the ad agency does not provide photos of the cars, complicating things further because you must find reference material which takes away from your rendering time. The Art director may also want to see pencil sketches before you start rendering the frames.
An example of one of my rough sketches which I place under a sheet of layout paper and trace for the final rendering.
One of many storyboards done for Subaru while I lived in New York. My many years of working in Detroit was a great help for me when doing automotive storyboards. I don't recall the ad agency or Art Director, but suddenly one day they closed shop and I lost a good client. Anything can happen in the ad biz.