You know what I do when I need a marquee retainer?
I go to the hardware store and look for a metal piece of corner molding, which I paint black and then cut to size. It works perfectly, and you can usually get a 10 or 12 foot piece for a couple of bucks. I probably still have 8 feet left on my current chunk of the stuff. This is MUCH cheaper than paying for a marquee retainer from happs.
I always try to find hardware store solutions. No shipping, often cheaper, and easily replaceable.
For cupholders try an auto parts store. But beware, cupholders lead to the dark side.