none. but usually if stay at 35% or higher they won't bother you. i used to have real dark on my mustang 5% back 3 windows and strip across front, 15% on doors, and 35% on top of 50% down the windshield, very dark, it was fine for me, but you could not see inside the car from any window when it was dusk out, looks awesome inside and out though. needless to say i got pulled over a few times in that car. then on my M3 i got 35% black onyx all around and 50% down the windshield, has a very clean look to it and you can see right through it, yet it looks tinted, looks awesome i will post pics soon. and i have never gotten pulled over in my M3. so i would say go for it. 35% on every window including windshield would be bad ass.
in NJ no tints where allowed sin the front windshild or front windows since 1985 !
WINDSHIELD tint = NO
FRONT SIDE tint =NO
BACK SIDE tint -(car)=ANY%
BACK SIDE tint-(MPV)=ANY%
REAR tint -(car)=ANY%
REAR tint -(MPV)=ANY%
L&R.MIRROR REQ.=YES(to have tint on you must have a L&r mirror on the car)
any tint you put on is grounds for getting stopped by an officer on the front (driver and passenger side windows)or the windshild
IS falls under the law obstruction of view!you can get a ticket also he can make you take them off on the spot or have your car towed if you refuse to take them off since your car is not suppose to be driven on the road with tint on the WINDSHIELD or
FRONT SIDE windows!