A question about car windo tinting (details inside):?

As I mentioned in an answer to a previous question I was pulled over by an Iowa State Trooper because he felt my front passenger and driver windows were too dark. He did some sort of meter test and determined that, in fact, they were too dark by Iowa State Law. However, I live in Wisconsin my car is licensed in Wisconsin and I bought the car from a dealer in Wisconsin. It also appears that my tint level is acceptable in Wisconsin. My question is ”Does anyone have any experience with window tinting laws and how they are applied to travelers from other states?

The ticket I got was for $80 and was not considered a moving violation. I have no idea what it will cost to remove and replace the tint or whehter I should remove and not replace because I will never be sure if it conforms to all the state laws. I travel over 5,000 miles per month in my car and cover 8 states but may cross into as many as 15 states. Any thoughts on this would be appreciated and practical knowledge would be great.