You truly do not know the history of the son. Unless the idea of good parenting is to forever hover over the children uttering continuous threats no matter how well behaved they are.
How is locking the doors hovering? If the kid was in the front seat, you grab his arm and say wait a minute son. If he is in the back seat you keep the doors locked until the car is actually parked. They are controlled at the drivers seat. You double check for approaching traffic then say okay we’re here. I am amazed at how so many people are clueless about car safety. And how few people understand what it means to be a parent. Duh, the kid won’t listen to me, Ethel. What should I do? I’m baffled. Should let him play with the chain saw? I asked him not to but you know those 5-year-olds and I don’t want to hover.
Any parent who allows a kid to jump out of a car that is not in park (automatic trans) is being negligent. This is the 21st century and car safety should not be a mystery to any one.