Yes it is legal. It doesn't even have to be in a case in the trunk either. Just keep it unloaded. We go shooting/hunting all the time and have dozens of guns all over the place. This is Utah, land of the guns. Store it safely at home don't let kids get access to it.
To establish personal identification and residence in this state for purposes of this part, a dealer shall require an individual receiving a firearm to present one photo identification on a form issued by a governmental agency of the state.
No. You do not need to register your handgun in Utah. POSSESS A HANDGUN ON MY PRIVATE PROPERTY WITHOUT A PERMIT?
Summary of Utah Gun Laws. Utah is a shall-issue state. Permits are issued by the Bureau of Criminal Identification. There is no permit, background check or firearms registration required when buying a handgun from a private individual.
How long does it take to get my permit? Utah is a “Shall Issue” state which means as long as you meet the minimum requirements, you will receive the permit. Utah law requires BCI to issue or deny a permit within 60 days. The 60-day period begins when BCI receives the application and processes the payment.
Non-resident proof of permit. If you reside in a state that recognizes the validity of the Utah CFP or has reciprocity with Utah, you must obtain a CFP or CCW from your home state and submit a copy of it with your application for a Utah permit.
How long does it take to get my permit? Utah is a “Shall Issue” state which means as long as you meet the minimum requirements, you will receive the permit. Utah law requires BCI to issue or deny a permit within 60 days. The 60-day period begins when BCI receives the application and processes the payment.