thank you Edmercer for your reply.

My idea of having a good physics code for a car would be to have precise settings adjustments like wheel positions with chassis etc.

In the adjustments that i am making in wheel sizes so that the care moves at desired is just based on trial and error and I am not able to get it just right ...

is there a better way of doing things or just trial and error ?

Thanks in advance ,
cheers !
Zazang