Booster Seat - suggestions and when to move

We currently own an RA (which we love, BTW). My dd is 2.5 years old, but is 35" tall...I noticed that her shoulders are even with the last row of the belt positioner and was wondering when I should move her to a "booster" type seat. She's only 32.5 pounds, so I'm not sure what to look for. Any suggestions or ideas would be greatly appreciated. I can't have anything big and bulky, which I noticed alot of the booster's were because I barely have room in the backseat for ds' infant seat with the RA (Passat sedan...my tushie you can fit 3 adults/3 carseats in the back ; )

Thanks for your help.

Rebekah

[Joolsplus2]

First, make sure that the cover isn't pulled down on your seat, making the slots appear lower...make sure that she's really even with the slots in the seat shell (it's a common problem,and 35" sounds a little short to be outgrowing the RA...though if she's very long in the torso, she may well be).
You want to look for a combo seat/ harnessed booster with tall slots (so, anything BUT cosco/eddie bauer/safety first, which are the same or shorter than the RA!), and with a front adjuster, either on the seat like the RA, or on the harness.
Here are some seats (bottom half of the page) that are good, and one should work for you http://www.car-safety.org/carseats.html...I know the Cargos are rather narrow. If you want to spend more for features you're used to, don't shy away from the Marathon...it's kind of wide, but on a small, high base, which makes it "mesh" well next to people/other seats (ie, it's easy to get to the seatbelt!)
HTH,

Someone on another board mentioned that the Graco Ultra Cargo (harness to 40 pounds, then booster) was about $48 at Sam's right now. You may want to look into that.