Yes, it's the new S class, from the earning call transcript:
" And to those who have not read the articles, they are saying them the new S-Class is being launched on May 15th in Hamburg, Germany that the new S-Class will be in showrooms this September and will offer Magic Sky Control as an option. So, while we can’t confirm this at this time, this SPD SmartGlass did appear on the new S-Class, it would be a highly significant event for Research Frontiers."
I did listen to the CC, they said they had NDA with Mercedes and could not comment directly. They did mention that some car publications have made reference that the S class had REFR technology. I have been aggressively looking for a direct comment that the S Class has Magic sky and as of yet haven't seen it yet. The Auto magazine I referenced mentions a variable tinted moonroof on the S Class but doesn't use the term Magic Sky so
I can't be 100% sure it is REFR. If anybody has more information directly saying that the S Class has magic sky in it please show me where Thanks