You know, I began picking through the piles of stuff that I got when I picked up the car and put in the frunk, a year later, almost. I found one large flat package in plastic I had forgotten about. I opened up and unfolded it and it looked like a windshield cover. However it did not fit, kept slipping off... until I figured out it was not for the front of the windshield, but for the overhead part of the windshield! Fits perfectly and cut out some of the overhead glare!
I wonder if they are still including that in the Model X orders now? It is handy.