I had my tints fitted after I got the car. However, on a recent meet I parked next to someone who had the Ford factory fitted privacy glass on theirs. The tint level was about the same. (pic of mine below. I only had the back 3 of mine tinted, all the fronts left the same as they are already at the legal limit as mentioned already.

As for window stickers, you are best to go for external ones.