Here is one more shot - looking towards east again, from a little lower to the ground (more like what another driver would see, rahter than a pedestrian). This shot should show the maximum difference because the sun is shining in on the other side of the car. There is glare in thes photo because I'm facing into the sun, but you get the idea. This situation shows when someone would see the maximum difference - when the car is between the viewer and the sun.
I'm trying to show you that it all depends on which angle you see things from, where the sun is at in relation to where the viewer and the car are located and how much light is gettting into the car.
Yes, there is definitely a difference. Florida says we are only supposed to go to 35% on fronts.
Here is my other car. I don't recall whether my Firebird has 20 or 35. I'm pretty sure it is 35 on the sides and 20 in the back because a cop stopped me once. He measured the window with a light meter but did not give me a ticket or warning. I recall he looked a little disappointed.
With 100 tinting: