Auto & Design is not quite a book, but it is printed matter and it´s not an advertisement**.
For anyone interested in getting some (but not much) insight into the car design process, you can take out a subscription to Auto & Design, one of two long-running automotive design journals. This one hails from Italy and is written in both English and Italian. The other is Car Design, which is Japanese and slightly more technical and academic in its style.
Auto & Design is a very, very glossy magazine and majors heavily on lavish and extensive spreads of photos of sketches, clay modelling and lush studio photos of the cars covered in each edition. With the exeption of Robert Cumberford´s commentaries (now discontinued, I believe), the text is full of nearly empty car design talk. This reflects the fact that car design is a branch of marketing and that car designers are a remarkably inarticulate group. They think in pictures and speech is merely a tool for gathering impressionistic word-salad. From my own experience, you can be quite precise about the
problems of car design but I have yet to see any of this written down (barring C. Edson Armi´s book on American car design). No, the reason you would want to look at Auto & Design to see the state of the art in automotive sketching. The standard of draftsmanship in the car industry is outstanding. What seems to be missing from most articles is the complexity of the car design process represented by the iterations and detail changes that week by week are involved in styling a car. The articles generally show what you would call a Whig view of car design, that the process illustrated was inevitable. This is where Car Design is a more interesting journal: they also show the rejected models which gives one a better idea of how the definitive design compares.
** The last edition of Auto & Design had a sponsored supplement as thick as the actual magazine devoted entirely to Qoros cars. It was titled Qoros & Design.