As I posted previously, you can make one yourself in a few minutes. I probably spent all of 15 minutes making mine, and it would be even less now that I've done a couple of them.
A couple of people have said that I should manufacture and sell them, but what I made isn't quite up to what I'd consider commercial quality (for instance, cuts were made with scissors so they're not perfectly straight), and to make it worth my time I'd have to charge too much for it, and I'd feel bad about that because it's *really* easy to make one.
Thank you jimf for your suggestion
The ABS plastic I used is probably even more susceptible to melting than is the dash display, though. Of course, it's also a heck of a lot less expensive to replace.
When I get around to making version 2 I'll post a template.
Another thing you could do, rather than adding a sun shade on the cluster, is to either paint or use a strip of contact paper on the lower part of the windshield. That would stop the lensing effect at its source.