Also, just so you know, the Camry doesn't have LATCH in the middle, just on the sides (in the 2007 manual it's on page 111, in the 2013 manual it's on page 123. Those are the two manuals I have).
$550 for two seats? And a small child? What's her shirt size? Smaller, spot on, or larger than her age?
For that you can get almost any combination of Safety 1st Guide 65, Evenflo SureRide, Graco My Ride, First Years True Fit, Safety 1st Complete Air, Graco Size4Me/Headwise/My Size 70, Diono Radians, Chicco NextFit, Maxi Cosi Pria (without TinyFit probably), and Clek Foonf you want.
Of those the Graco Size4Me is the tallest and will get her to 40 pounds rear facing even being so short. However, some have harness issues so keep the receipt. The Chicco NextFit and Clek Foonf are next tallest. The Foonf is the most expensive, but you could still buy one and then a Guide 65 or SureRide and be under budget. It rear faces to 50 pounds, but your daughter will max out on height before 50 pounds. The NextFit is a very easy seat to install and use. Then the Dionos are next and they work well in Camrys of all ages.
Wendy