Is there really a restriction defined by a number (70%)? Because I have found another
information about PA tint law here. It´s stated there that any tint is legal as long as it´s possible to see into the vehicle. It´s a resource written by a paralegal so I suppose the info should be quite relevant!
yes, 70% or higher for the front door windows. anything lower than 70% will be considered as a vision obstruction. whats possible to see thru is a very subjective matter, but realistically you dont want to go lower than the 70% otherwise you will simply give the police a reason to stop you at any time, for any reason which will allow them to go on a fishing trip with your car.
can you go lower than 70% and get away with it? absolutely.. people do it daily. you can prob go as low as 35% on the front doors and still be OK, but its possible you can be stopped at any time.
if you are into illegal activity i highly suggest not having any tint at all. the last thing you want is to get pulled over for tint while doing something illegal.
the rear door windows and rear windshield can be tinted dark, even as low as 5%.
i live in PA, my rear doors and rear windshield are 15%. my front doors and front windshield are clean, no tint.