Had a cop tell me that my factory glass wasn't factory and too dark and now I have to go to court.
The rear is 20% and from the factory. It's integral to the glass.
I imagine what the officer was confused about was that he/she didn't understand that the CT is actually considered a "truck" and not a car.
In my state, the lovely Commonwealth of Massachusetts, sedan's may not have any tint darker than 35%. But because my CT is *not* a sedan, but rather a "truck," Tint is allowed on any windows other than the front windows.
My vehicle registration reflects that the vehicle is a light truck / suv... if yours does not, the person at the DMV perhaps screwed up and you should get some official documentation from Honda that explains the designation of the vehicle.
(This designation also has affect on federal regulations such as smog, weight, etc... so it's an important designation and should be relatively easy to find official documentation on it.)