Every driver who transports a child under the age of 18 years in a motor vehicle, is required to have the child restrained in a car seat or seat belt. Minnesota Child Car Seat Law and Steps.Most car seats have weight limits at 35-40 pounds rear facing. One of ours goes up to 50 pounds. The new law states kids must remain rearfacing until a minimum of 2 years old. Minnesota car seat laws are changing as of Aug. Minnesota has recently passed a new child restraint law which may change the way your children travel within a vehicle. Using a car seat is the law in every U.S. state. Woodbury Public Safety's Child Passenger Safety Technicians can assist residents with the proper installation of child seats. Most will work from birth up to 65 pounds (30 kilograms).