On my 2006 Plus 4 I do 80% of my driving with Tonneau cover on. It fits neatly over folder easy up roof. I did a mod (thread on TM) where to cut down Tonneau cover inflation/flap I fitted a short strap from cover edge to passenger seat belt fastening using Tennex fasteners and an ebay male belt buckle. . It transformed the Tonneau cover driving experience - for the better.
It seems crazy to me that on the new CX models a Tonneau cover is not an option and threatens warranty. Thats NOT "progress".