The royal baby is only a few days old, but Prince William and his wife Kate's safety practices as parents are already being questioned by the president of a St. John's car seat safety group.

Shelly Bauer, president of Kids in Safe Seats, said the new parents were not using best practices when they put their royal bundle in the car.

"I have the same concerns that I have with all new parents, and those concerns are that they don't know how to use their car seat," Bauer said. "And about 90 per cent of brand new parents don't know how to use their car seat, so this is not unusual."

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The new father seemed pretty comfortable swinging the car seat into place, though some critics carped at how the new royal baby was strapped in. (Reuters)

According to Bauer, there were several things that concerned her, including the amount of bundling clothes the baby was wrapped in, as well as the lack of strain to ensure the car seat was properly locked in place.

She said the only way many parents find out they haven't been using their car seat correctly is when they get into an accident.

"You have to remember that the point of collision is not the point to ask yourself, 'Did I do this right?'" Bauer said.

"Car seats are one-use items, and at that one point of use, they have to be working properly, and they have to be used perfectly. So, was he in danger? If they had had a collision, he would have been in severe danger."

She said the Duke and Duchess of Cambridge aren't the only ones, and there is a surprising number of parents who are not using their car seat properly or, in some cases, at all.

"When we do roadside checks with the police, we find 100 per cent incorrect," she said. "We have small children sitting beside the car seat while a bag of dog food is strapped in the car seat. We have small children bouncing around the front seat with a perfectly viable car seat in the backseat, but [the parents] say, 'Oh, he doesn't like to sit in it.'"

Bauer said the best way for parents to learn how to correctly use a car seat is to get in touch with organizations in their community, similar to hers, which offer free sessions to new parents.