I inherited my dad's 1966 first printing of Grif Borgeson's
The Golden Age of the American Racing Car, which remains a massively impressive work, IMO.
One of the most fascinating automotive books I've read in a long time is Antoine Raffaelli's
Memoirs of a Bugatti Hunter from 1997, where the complete histories of over 100 Type 35's (and numerous other Bugs) are tracked down. Sounds dry, but a great read with many excellent, never before published photos:
Tim