A trooper stopping a car in Utah with a suspected “impaired driver” on a US highway was bemused to find a five-year-old boy in the driver’s seat.

After seeing a vehicle driving slowly and weaving in the left lane of the Interstate 15 freeway, the trooper turned on his siren, and the driver neatly pulled over to the side of the road.

Dashboard camera video posted by the police captures the conversation between the trooper and the driver, which has since been viewed on YouTube almost 760,000 times.

“You’re five years old?” the trooper says.

“Wow!”

He then asks the child where he learned how to drive and takes down other details.

The boy, who was not identified as he is a minor, said he had left home in his parents’ vehicle after arguing with his mother, who had told him she would not buy him a Lamborghini.

“He decided to take the car and go to California to buy one himself,” the police said in a tweet, adding: “He might have been short on the purchase amount as he only had $3 in his wallet.”

In a lovely ending, a Good Samaritan who lived in another county heard the story and gave the young boy a ride in his Lamborghini Huracan.