[Al Skierkiewicz]

JJ,
I saw your picture in your other post. Most often, teams will use gussets (triangular plates) where you are planning to use clips. One of the advantages is to provide angular support in a one piece solution. The plates are easily attached using pop rivets or threaded fasteners. As an example in your front vertical post, a triangular piece of aluminum attached to the back of the junction would prevent the joint from rotating left to right while providing a method of attaching the post to chassis bottom. A plate on either side provides twice the support. This solution would cut your parts count in half.