ok....

1. Yes, you can develop a realistic car game using A6 pro and 3ds max...

2. Havok....it should be possible....you will "just" have to write havok as a plugin....

3. one physic object means, that only one object is able to behave e-g- like a car at one time...for a car game with AI-cars...i would suggest buying A6 pro...

4. Go at the download page...i saw there a car-game with a buggie...

5. Newton is a physic-engine which you can use as a plugin for every version of 3DGS.

I hope, i could help you....

Regards Efrint