@Douglas Thanks for reaching out!
We do have a process by which a customer, such as yourself, can order products that are not carried by REI that are from companies that are partners with REI. The process is called a 'special order' and it can only be completed at your local REI store. Bear in mind that while we place the order, shipping and processing is done by the vendor and can vary. The first thing you will need to do is have your local REI check with Thule to make sure the awning you want to order is available.
Hopefully this helps!