Here is one I made a few years ago. If you want it, even just as a template, hit me up in PM. It was a proof of concept, so it's thinner with stronger, more visible supports. Quick release, pull four pins and remove. It seemed to amplify cross winds on the freeway. That is why it stayed a "concept" for me.
Nice work..On convertibles the rear wind restrictors really help. Frontal air blockage (mainly windshields), cause a low pressure area in the cockpit which causes high pressure air to rush in from behind. The lit, etched ones are beautiful but are correspondingly expensive. A plain jane cut piece of 1/4" plexi with an inexpensive price would probably be a popular item.