I have a Black Britax Regent Car seat available. It will hold your child in a 5 point harness up to 80 lbs. To see the importance of this, view this video on utube. Fair warning though, if you are a mom, this is going to tear your heart out, especially if you have a little boy. http://www.youtube.com/watch?v=azgBhZfcqaQ
This seat did not work in our car because the car is too small for it and unfortunately, we can't buy another vehicle just to keep the car seat. If you want the best car seat there is on the market, this is it. We paid $269 when we bought it and it was only used for about a month before our sons legs got too long.