Quick update: I have looked at my mock up and decided on the reinforcements to make the chassis more rigid: on the left is the new chassis and on the right is the old one. (I used Google Sketchup)

I updated the cad model on the:

• rear shock tower was quite flimsy before
• front shock tower/suspension mounting points were fine, but needed lateral reinforcement
• roof bent at the joint and added no stiffness to the chassis
• where the side of the chassis attached to the rear shock tower.