How to enable “Guest Account” with InstaDMG or from the CLI

I have been successfully using InstaDMG for sometime. Thank you very much to afp548! It's made life so much easier. Depending upon my requirements, I make some modifications for my image during the InstaDMG build process. Some modifications I make using a "first boot" script. I would like to add the ability to enable the guest account for an image. I have played with quite a few options, including: • applying local mcx to change the preference pane setting. • adding a guest user using createUser • adding a guest user by adding a plist to /var/db/dslocal/nodes/Default/users and /var/db/shadow/hash. None of these has worked, successfully. How do you enable the guest account from the CLI? Furthermore, can a package be created that will enable the guest account using InstaDMG?