And states do not require active service members to reregister their cars when they have moved on orders.

They do still have to comply with local laws, which makes sense. Just because you have Florida plates does not mean you don’t need all weather tires in Minnesota.

I'm aware. I'm stating explicitly that I think that at any point in time, the number of service members who have tinted windows that are legal where they are stationed but would be illegal in a state that's within an hour from there is very small. I asked you to elaborate on how many you think there are, but it honestly doesn't sound like you think there are very many either based on your responses.

I'd advise them to not install potentially illegal tint on their cars if they're constantly moving to places with strict tint limitations.

Problem solved.