Aerodynamics of Road Vehicles, 5th-Edition
 

The book is $ 225 US.
The index can be viewed online at SAE International's website.

It is a massive book - something like 1300 pages - and greatly updates previous editions.

Not infrequently, it states that is is making points that are contrary to previous editions, although of course the great majority of content is in agreement with the earlier books.

Some examples of content where a changed approach is taken over previous editions includes Page 285 (difference in treatment of flowfields in the wake) and Page 309 (how a spoiler works on a fastback). There are also many others.

Without doing a back to back comparison to be certain, the 5th edition also seems to qualify some former more definite statements eg suggested boat-tailing angles.

You won't find a better coverage of vehicle aero (it includes motorcycles and trucks) anywhere. I got my copy second hand but I had to wait a long time for it to turn up. Be aware that second hand prices are sometimes higher than new!

Here's the SAE link - https://www.sae.org/publications/books/content/r-430/

The very extensive table of contents - https://www.sae.org/images/books/toc_pdfs/R430.pdf