In a bid to find out how much parents knew about the new laws and how knowledgeable they were about fitting child seats, What Car? carried out 30 on-the-spot tests. Parents with children under 12 years were interviewed and their child's car seat checked by our experts to see how well they were fitted.
In our checks, 65% of parents had not fitted their child seats correctly, even though about 80% said they had received proper instruction from store staff when they had bought their seats.
Most failures were due to twisted belts, which could cut into a child's body in the event of accident. Loose harnesses or slack adult belts securing the seat in the car also failed the test.
Most of the parents who had badly fitted child car seats claimed they had fitted them in a hurry, and said that they take more care on longer journeys. However, a quick drive to the shops is usually more dangerous than a long journey - most car accidents happen on short trips and on roads with which the driver is most familiar.
About 90% of the parents we questioned during our on-the-spot tests were aware that new child seat laws had been introduced, but only about 35% had specific knowledge of the regulations.
Ruth Wilkinson, 34, a nursery nurse from Watford, said: 'I don't think there has been enough information for parents - not just about the new laws, but about how to fit child seats.
'A parent can go into a shop or superstore and buy a child seat off the shelf with little or no advice, and be convinced that the instructions are good enough.'
Three major retailers of child seats, Mothercare, Toys R Us and Halfords, said they all offered advice to parents on fitting child car seats properly.
A spokesman for Toys R Us said: 'We were closely involved in the Department for Transport's campaign to tell parents about the new laws. We have members of staff in each store who have been specially trained to give advice on types of child seat and to help with seat fitting.'