It could be you need to use the industrial and not the professional.
I'll be ordering the Dunes Tan in the industrial line and try the bed of my Rampage. I do plan on using their Heavy Duty Rust Inhibitive Primer as well. I do however want to wait for warmer weather, not so much for the paint as me.

http://dragosupply.com/drago/servlet/CyberVendor/category/G4501296/catalog/group.jsp/