well i posted a decently long post about window tint a while back but not sure where it got off to.
The 4runners do not come with factory tint. As you all know, tint is a dyed layer of film that is put on your windows. Our 4runners have their glass actually dyed 20% from the factory and then installed.
As stated before there are contributing factors to getting your front 2 windows to match your rears such as light coming from your front windshield as well as the sunroof.
To put it as simple as i can, to match the back windows you want a small(you can keep it legal(to the AS1 line)) tint banner on the front windshield which can legally be as dark as you want it as long as it doesn't go below the AS1 line, combined with 15% on your front two windows.
I am not going to go into legality issues with tint.
quick description of percents that tint comes in:
50%: clear, but still 100% UV protection
35%: Legal limit in most states. You can still see through 35% but it is noticeable at night and cloudy days that you have tint.
20%: Allows you to see a silhouette of a person along with their facial features.
15%: Allows you to see a silhouette with no facial features.
5%: basically blacked out unless lights are shining into the windshield or lights are on inside the vehicle.
All of these descriptions vary depending on weather and lighting.
source: i have tinted windows for 4 years and have tinted my 4runner windows through every tint and more. I currently have 5% over 5% on the front 2 and 5% over the factory dye on the rear, 5% banner on front windshield. I love privacy and don't have to worry about seeing at night since all the windows go down.
Let me know if you have anymore questions, id be glad to answer them.
Here are a few of my windows on a very sunny day at the beach
You can see in this one that the back passenger window is down.
Another look into the inside:
and the artsy shot: