They can only hold you to the laws in your state of residence. If your vehicle passes in your state it is legal everywhere else. Just ask an attorney on that. And yes it could be constrewed as selective enforcement. I played that game before. I had a right hand drive VW bug. I didn't have a mirror on the left side it was on the right drivers side. Pullled over three time in one month and given a ticket for it by the same UHP. The first time he pulled me over was because "it didn't look right". He went back to his car and came back with the ticket. The next two times he pulled me over was to check to see if I had moved the mirror. No I handn't so, ticket.
Went to court on this. and told the judge about what happened. The judge said "it sounds like selective enforcement". He dismissed my tickets and told the officer that he was to give me a written apology.
My brother in law had the same problem with tint when he came to St. george. He lived in Vegas. Went to court and fought the tickets. He no longer has any problem coming into St. george.
They cannot ask you to drive around the state or be arrested if you met all certifications in you local residence. But if you live in that state they can sure give you all kind of grief.
Couple things. Yes, they can "make you" drive around the state if you don't want to comply with the laws. Ask the OTR truckers how many permits they have to pull for different states depending on what they are hauling. Also, that cop that gave you the tickets was an idiot (if what you say is true). Not an idiot for giving yo a ticket for something that's not legal here, but for giving you a ticket for something that's 100% legal here. All Utah law says regarding mirrors is that you need to rear facing mirrors on vehicles 1968 or newer, one on the driver side and one rear view mirror, unless you have tint or other obstruction of the rear view mirror than you have to have a passenger side mirror. It doesn't say anything about right of left, it clearly uses driver side/passenger side. Lastly, when was the last time you got arrested for a traffic violation? Unless there are other reasons to arrest you, you won't be so quit being melodramatic over a traffic citation discussion.
It's not only Utah that does this, just about every state does (and they all have the right to). Go look at many of the state visitors sites. Many of them have a section called "top 10 laws you might want to know about when visiting <insert state here>. Like I said before, ignorance is no excuse for the law. Military is a different issue. You are only responsible for the laws of the state you call home. That was already covered earlier, same thing for students I believe. Otherwise you have 60 days to get your car registered and driver license changed to Utah once you call Utah your home.