California, which has more drivers than any other state, has raised its cutoff age for car seats to 8. The new law took effect Sunday, with stiff fines for parents who don't comply. Children must be buckled into booster seats in vehicles until they turn 8 or grow to a height of 4-foot-9, under SB929 by Sen. Noreen Evans, D-Santa Rosa. That's two more years than under the previous law, which required the restraints until children turned 6 or reached 60 pounds.