This thread is for links to automotive sites with accurate and technical information on all aspects of car design and construction.
Also feel free to include BOOKS along with a quick explanation.

No links to "my mate has a street legal civic that does 10 second 1/4 mile" sites please

I'll start the ball rolling with

Mulsannes Corner - an enthusiast examines Le Mans cars (primarily with an aerodynamics interest )
Locost 7 - Very informative locost 7 design information
Puma racing -- This is a cylinder head tuner, I'm not vouching for his work, but take a look at his information on engine tuning etc. further down the page.
Net Composites - Lot's and lots of information on composites
How stuff works