FWIW, I live in AZ -- and took delivery in early June last year, so I have an AZ summer of experience with this. I had the side and rear windows tinted with 3M Crystalline about 4 days after getting the car. I did not have the pano roof or windshield tinted.
Heat penetration from the side windows was greatly reduced with Crystalline -- my first few morning commutes did not have tint and I could feel the sun's heat coming in. After getting the tint, that was gone.
The Pano does not need any additional tinting and the stock glass has very good UV reduction qualities. Even on the hottest days of the year, I could not feel any solar radiation coming through the roof on my head. If I reached my hand up above my head, I could feel a little bit of heat as my hand got close to the glass -- but it was very subtle and likely more an effect of heat rising and cold falling -- so the car was naturally cooler lower down with the A/C running...
I am considering getting my windshield tinted (using the lightest near-clear shade) before this summer -- even though its illegal. I could still feel heat coming through it last summer...
