I have factory deep tint glass in the rear and I had the front windows tinted to match 20%. I also had a 5% strip installed on the front windshield.
Here is a pic:
If you look close you can see the vehicle going by and the street behind my KJ through both tinted windows.
PA Legal mumbo jumbo: Unlike other States, which explicitly state a percentage in their law, Pennsylvania does not. Therefore it is necessary to make a 'reasonable' estimate. Based on common sense and the Law in other States, it appears that tint with a transmittance much below 25-30% may not permit a person to view the interior and would therefore be ILLEGAL under current PA Law.
In Philly here tint is all over the place, alot of vehicles have 5% and their front windshields down to half of the window. I have even seen "daily driver" vehicles with orange, red and blue color tints all around. Talk about ugly!
For 20 years I have had tint installed all around in every vehicle I owed and never had any problems. The darkest i've gone was 5% on my very first vehicle and it was way too dark. Could not see at night and had to roll down the windows to see anything, and backing up was a pain in the ***!
I agree with the other poster that generally you will get pulled over for another infraction and then possibly be issued a citation for dark tint. The issue that pisses off police (watched too many reality COPS shows, so I know) is that they cannot not see in your vehicle when they pull you over. Makes the Police go into high defense mode.
My thought is that if I ever get pulled over for something. First thing I will do after I put the vehicle in park and shut off the ignition will be to roll down the front windows and turn on the interior light so that the Police has an unobstructed view into the vehicle. This signals to Police your not going to run and have nothing to hide.
In this day and age the Police have more important things to worry about than to stop you for tint on your windows.
I have a brother-in-law that has had two different sports cars that he installed tint on the rear windows only. He was afraid to be "hassled" by the law.
More important things to worry about, just do what you to do with your tint. I definately would not suggest anything lighter than 20% though. 35% is way too light.
Just think about it technically with alot of jeeps and other 4x4's various other things could be illegal depending what state your in. (i.e. tire projection past the wheel well, height of bumpers, size of tires, etc., etc., etc.)