I contacted Winnebago and they provided me with the name of the company that manufactures their Roof Racks, Ladders & Bike Racks for the Winnebago Class B RV's. They're made by Summit Products in Altoona,IA, also known as RVStainless.Com or
info@Summit-Products.com
Summit was contracted by Winnebago only to manufacture the Class B Roof Rack, Ladder and Bike Rack. Summit has not been requested to provide any accessories for same : Kayak racks, clam shell containers, Etc.
Finding accessories that would attach to the Roof Rack was a tedious process due to the shape of the roof rack rails which are elliptical. I finally discovered the YAKIMA Jay Low (Collapsable) Kayak Rack (Part# 1034488) which is designed to fit round, square and elliptical rails. It just so happened that West Marine had them on sale at 40% off. I bought two sets and they fit perfectly, are well made and since they are collapsible can remain installed when not in use. I also discovered at West Marine the Boat Roller which is a kayak/canoe roller device that you attach by suction cup to your vehicle which helps you to roll the kayak up to the racks without scraping the vehicle paint.