Re: Toddler/Booster seat?
If you can afford it, I'd go for one of the Britax line. I have a Marathon because that's the only one approved for use in Canada, but I know there are lots of others available in the US. A Britax seat will keep your child harnessed much longer than other toddler carseats, and I love how easy to use mine is.
A much less expensive option is the Cosco Scenara. Both my DS's ride in Scenara's in my parents' vehicle. DS1 is 35 lbs and over 40 inches tall and he still has a bit of growth room in the harness of the Scenara. I believe they're available in the $50 range in the US. I've found that it fits well in several vehicles, including my father's Subaru, which has had trouble with other carseats.
DS1 (12/02), DS2 (03/05)