Check out "Race Car Vehicle Dynamics" by Milliken and Milliken published by
SAE. It'll set you back $85 or so, but it seems to be the definitive book
on the subject.
Also, there is a group of us who play around with a program called RARS
which is a very simple point mass simulation of vehicle dynamics. The
source is available at ftp.ijs.com in /pub/rars (hope I got that right).
It's primarily intended as a platform for competition between programmers
attempting to write AI driver programs.
Dave