How worried are you about getting pulled over, and how bad are the cops in that area? If you hear that cops in your area are particularly bad; then go for the 20% so at least its close. From the outside (especially looking through the car from the side) 5% is going to be obviously illegal, whereas 20% may not be quite as obvious from a quick glance from a cop (unless of course the legal limit is something stupid like 40 or 50%.

Personally, I have 5% all around, and 50% over the whole windshield. I love it, and it really helps keep the interior heat down; but also being in PHX, the legal limits are pretty low, and cops seem to be pretty lenient about it.

But it seems that the two choices the OP gave us are both illegal in his area.

Also, I would think having those tiny corner windows super dark compared to the rest of the car would be kinda goofy, but thats just IMO.

I'm all for keeping the car legal though- I did my Impala right at the legal limit out here since I drive it much more, and don't want to ever have the hassle. With my GP and monte, I'm willing to risk the slim chance of getting pulled over out here for a better look on the car, and a cooler interior.

 

mine's 20% all around (cop said it's 14 lol). unless the sun is shining right on the car, you can't see inside at all. even then all you can make out is silhouettes. sometimes it sucks backing up though. it made a big difference with heat on the inside (my leather is happy). any darker and i'd say you're at risk for running into someone or something at night.

 

down here in SC cops are so chill when it comes to speeding *ahem* burning out, speakers, open headers and most car related stuff. they are mostly about chasing drug dealers and people like that. hell a sheriff that works part time at AutoZone helped me install my HID's and his truck had HID's and 5% all around tint. i normally see a lot of people with either limo tints or the cheapskate tints that look hideous purple. looking like i'm gonna go with 20%.

 

The actual %tint is not what will get you a ticket, as selling it at Autozone ect would be illegal as well. Federal law mandates that any imported item that is intended for automobile use in the united states meet SAE standards. with that said manufacturers tint windows from the factory to keep ahead of UV safety standards, usually ~2%.

The real concern of law officers is visibility in and out of the vehicle. The restricitons on %tint are mainly for guidance as once you venture sub 35% on consecutive windows the overall light penetrating the glass is reduced significantly as to only tinting two windows at 2%. By checking your state laws there will be a law stating the amount of light that would be present in the front two seats (most likely in lumen or candela) and this is the number you need to be most concerned with.

An officer would use a photocell placed in the front seat, with the doors and all windows shut, then measures the amount of light that penetrates the windows. If this value falls below highway safety laws then you WILL get a ticket (most likely a warning the first time) which in Ohio if you show the court within 2 weeks that you have fixed the issue the ticket is waved.

A common practice is that as long as you have the two mirrors on your doors the rear windshield literally doesn't have to exist (Limo black). Since the lumen reading is performed in the front seat the rear passenger windows do not directly effect the reading and can also be very dark.

keep in mind of the "cavern" effect that is produced when looking from a lit area into a dark one. The difference in apparent light will play a large role in how often, if at all you are pulled over. For instance, the vehicle will look much darker inside if it is a very sunny day outside, even if you are within the legal lumen range.

I just wanted to point out that this is not a simple cut and dry case of, "5% or 20%?". There are many ways to set up a tint to be functional, legal, and sweet looking.

quick and dirty setup that is all of the above: (% as light penetration)
front windshield; top down to review mirror ~20%
front side windows; 35%
rear passenger and windshield; ~2-15%

The combination takes advantage of the cavern effect to slightly multiply the effectiveness of all tints.
below is a similar tint i have on my truck
2% rear 35% sides

 

This is what I would have liked, 5% on the rear. I have 20% all around

 

i did 20% all around....i want it darker so im doing a layer of 5% over the 20 on the small side windows and the back one =]