Hi Bill, I'm in Las Vegas so I fully appreciate the importance of not just a shade, but one that is very efficient and easy to live with. Like you, I prefer the custom fitted ones. Particularly the thick, rigid, pleated type with insulation built inside and a reflective face. Unfortunately I've found the custom ones from CoverCraft (not to be confused with CoverKing) have proven to be inferior quality and do not last - especially when the high price is considered. I'll try another brand next time.
However that does not matter since no one offers a custom fit for the X as you say. So far my X's are all still in the process of complete restoration/customization, so I have not tried to find a shade for them yet. I'm sure you have already tried most of the usual "generic" ones, and just like me find they all pretty much suck. Not sure what I'll get but I am interested to see what you come up with. Please keep us posted.
On a related note, I once tried a new (at the time) product that was a custom fitted exterior sun shade. It covered the roof and all windows with a fairly thick insulated material that had a reflective face. It was secured by elastic cords and soft covered hooks that clamped over the fender lips. The cooling effect was great, much better than a inside shade. But the thing was a pain to put on and off, especially in the typical high winds we get. And it did not last long before the desert sun rotted it. Plus the elastic cords left some minor marks that I had to polish out. It was rather costly and a fail. I've found any exterior car cover to be impractical here as well. For the same reasons; too windy here, sun rots them quickly, and they tend to leave marks due to the fine sand that is in the air here. Of course I'm referring to outdoor use, I don't have room for any vehicles to be kept inside (too much equipment in the garage fills it up).