The boy remained in the SUV after arguing with his mother, who said she would not buy the luxury car for him, the Utah Highway Patrol said on Twitter.
A trooper spotted the vehicle weaving on Interstate 15 at 30 mph, the Utah Highway Patrol said.
"How old are you? You're 5 years old?" Trooper Rick Morgan says in stretched camera footage of the traffic stop. "Wow … Where did you learn to drive?"
Morgan told KSL-TV that he had to help the child get the SUV in the park.
"He sat in the front of the seat so he could reach the brake pedal to keep the car stopped while I was standing there," he said.
When he was pulled over, the child told the trooper he was planning to drive to California to buy a Lamborghini for himself. He had $ 3. The starting price for a new Lamborghini is around $ 200,000.
Morgan says no one was injured, and it will be up to the local prosecutor's office to decide whether to file charges against the parents, who had left the boy in their sibling while away from home.