You were the safe caregiver and kept your child rear facing until the limits of the seat. Good for you! Now your child should use a carseat forward facing. If you made it to 35 pounds RF, you must have a nice convertible carseat. You can continue to use that seat (as long as it's not expired or recalled) for foreward facing.
Make sure you switch the LATCH belt or vehicle belt to the belt path designated for Forward facing. Make sure the harness straps are at or above your child's shoulders (you can't use a harness slot below the shoulders now), and follow the seat's instructions for installation. Make sure you use the top tether, even if you're not using LATCH. If your vehicle does not have a tether anchor, contact your dealership about having one retrofitted.
If you can't use your convertible seat any longer (it's expired, it's recalled, or you just don't like it), you have some choices. You'll probobly want to buy a Combination seat. A Combo seat is one that will harness the child until 40, 50, 65, or 80 pounds forward facing only, and then it can be used as a belt positioning booster afterwards.
How do you know if the child is to big for the forward facing seat? The seat is outgrown if 1 of 3 things happen:
1- Your child reaches the weight limit (40, 50, 65, or 80 pounds)
2- The top harness slot is below your child's shoulders
3- The top of your child's ears are even with the top of the carseat
Unfortunately, number 2 or 3 usually happen before number 1. So, weight is not always the best thing to look at when selecting a new seat.
When looking for a new seat for forward facing, here are some thing to consider:
-You want to have high top harness slots (16-18 inches from the seat of the carseat)
-You want a high weight limit, preferably 65 pounds (some 80 pound seats will be outgrown before the child actually weighs 80 pounds)
- And with all carseats, you want to make sure the carseat fits your child, fits your vehicle, and fits your budget.