I have heard rumors that say they have to be rear facing by law but have never found that to be true when I googled that states laws about car seats.
I know that it is safer for all passengers to be rear facing but the facts are that if your child is too big to be rear facing they are in fact in more danger of the seat flipping up because their weight is not balanced well.
So google them.
******************************************************
California Highway Patrol page
http://www.chp.ca.gov/community/safeseat.html
"Children under the age of 8 must be secured in a car seat or booster seat in the back seat.
Children under the age of 8 who are 4' 9" or taller may be secured by a safety belt in the back seat."
**********************************************************
http://www.carseatlaws.com/california-car-seat-law
"Rear Facing Car Seat
For a newborn or infant up to 20-35 pounds
Until at least one (1) year of age and twenty (20) pounds in the back seat.
Car Seat may never be facing forward"
"Forward Facing Car Seat
A child must be over one (1) year of age and weight at least twenty (20) pounds
Facing forward only."
*************************************************
So as you can see. California has laws that kids under 8 years of age should be in some sort of car seat, whether it's rear facing or a booster. There are exceptions though.
They do not "have" to be rear facing after 20 lbs. They do not "have" to be forward facing at a certain age.
If you are about to spend the money to buy a new car seat get the best one that fits your budget, child, and vehicle. I have seen parents get these huge long car seats that would not even fit in a truck. Then they struggle to get them in their smaller cars or vans. I had one given to me when my grandson was a new born. It was a convertible one and very nice. The problem was that it was to tall that I literally had to move the passenger seat all the way up to the dash to get in to sit correctly in the seat.
This car seat was not safe for him. If we had in fact had an accident he would have flipped towards the back since the weight of the car seat was towards the top. It was meant to be a rear facing seat with a shoulder strap holding it next to the seat back.
Your child is big enough and old enough, when he turns 1, to be forward facing. If you choose to keep him rear facing I suggest you do so in a way where his feet are able to fit properly on his seat and the seat is flat to the seat on the bottom.