Just FYI. The Cosco scenera is great unless you have a big kid. Even as a spare seat, you want some thing that will say rearfacing for a long time. We had to replace ours at 20 months. DS already weighed 35 lbs. Also, the FF limit is only 40 lbs so she'll need something else eventually.
This is true, but of the low-price options it still is the best bet as far as shell height and RF weight limits. Also, I may be wrong but I think current models actually RF to 40 lbs and head even with the top of the shell instead of 1". ***this is something that someone buying it needs to check in the owner's manual, but I recall reading it on car-seat.org at some point***