I have a black R33 gtst..tinted @ 5%.
Don't get hassles by the cops.
Aslong as ur 2 front windows are @ 35% u can have the rest as dark as u want.
Actually, it is still illegal to have your back windows darker than 35. Only sometimes you can get away with it, becuase the brand new cars are now coming out with glass at below 35 from the factory.
Your insurance can be voided becuase of that tinting at the back.
I simply get darkest legal all way around so you are in the right
aquilius - ask the folks who is doing your tinting they will know everything related to tints