In California, children are not permitted to ride in the front seat of a passenger vehicle until they are at least eight years of age. Children to be correctly restrained in a car seat or booster seat until they are 8 years old OR 4'9" tall.The new law also requires children under the age of two be secured in rearfacing child passenger restraint seats, which meet federal standards. California law requires a child to be 8 years old to ride in the front seat. Families that meet the income requirements and complete the class will receive a free car seat. Clinic in the Park's Boosters in a Bag. A CPS Technician will: Fill out car seat check form to document the process. California law requires children to remain rear-facing until age 2. If a driver's vehicle only has two seat belts in the back seat, only two passengers may ride in the back seat and both must use seat belts. The new law also requires children under the age of two be secured in rearfacing child passenger restraint seats, which meet federal standards.