Occasional-use carseat for a 32-lb 34" 16-month-old
My son is 4 and can use a booster seat, which is easy and cheap.
My daughter, on the other hand, is 16 months old. I know that technically she should still be rear-facing, but we had switched her to front-facing before we gave our car up in August simply because her hand-me-down carseat from her brother had to be switched to front-facing at 30lb and she had already hit that at 1 year.
We left our carseats with my parents back in Ohio, and there isn't a practical way to get them all the way out here.
So, P101, what would be your recommendation for a carseat that will see only occasional use (every other month at best), have to be carried on the bus to get to the Zipcar location, and will need to accomodate a 16-month-old who now weighs 32lb and is 34" tall?
ETA: We're also on a really tight budget, so price matters, which is part of why we decided to give up our car.