M.L.
Hi,
My son outgrew his infant car seat at 5 mos. I bought the Britax convertible car seat (Marathon model). It's a bit pricey but I have been very happy with it. It's super-easy to install--we've moved around a lot since I bought it--and I like that he can stay rear-facing up to 35 pounds. Then it can be converted to forward-facing up to 65 pounds.