Yes. Utah Criminal Code Title 76 Chapter 10 Section 2202 "Leaving a child unattended in a motor vehicle". It is a class C misdemeanor to leave a child younger than 9 years old alone in a car.
Never?
Am not really sure, but if you happen to see a child in a car unattended call the policeimmediately in cases such as that Child Protective Services will get involved, and authorities will file charges under "Willful harm to a child" MORE Yes, in CA we do have laws about leaving children alone in the car. Contact the police.
Children who are about 80 pounds can sit in the passenger seat in Utah
no specific age, but if your planning on leaving your child in a car, your an awful parent
Under certain conditions, it could lead to animal cruelty charges.
10 im guessing
It should be 13.
Call the police. At the very least, it is not safe to leave children in the car alone--they can release brakes, suffocate, get extremely cold or a myriad of other problems that can come up with a child's imagination. It seems more convenient to leave them, but really quick errands have a way of not being that way at all.
I found a really helpful PDF put out by the Utah Safety council. According to it, there is no law regarding children riding in the front seat of the car: http://www.utahsafetycouncil.org/assets/pdf/utboosterlaw.pdf It is recommended that children under age 12 ride in the back seat, or to turn the airbags off if a child under 12 is in the front seat, but there is no law saying you have to.
In Utah, a car can legally carry as many passengers as there are factory-installed seatbelts.
In KS, this would fall under the child endangerment law. There isn't another specific law yet about when, how long, how old, etc you can or can't leave a child in the car. But under child endangerment, the officer can arrest the caregiver and take the children into custody.
You can go to dmv.com to search for car insurance in the Utah region for free.