Booster seat question for older child

[momathome]

Liza is going to be 8 in February but she is on the small side (about 47" and 48 lbs) so I planned on keeping her in a booster until she was at least 9 or 10. She has been using the Britax StarRiser Comfy booster since she was 4. We have a 2003 Mazda MPV that does not have side curtain airbags and I just saw crash test ratings for side impact crashes with minivans and the MPV received a poor rating - not what I wanted to see! Our van is only 2.5 years-old and we plan on keeping for at least another 2.5 years. My question - do you think it is worth upgrading to a Britax Parkway with the EPS foam or do you think the StarRiser is adequate given that we will only being using it for another year or 2? TIA!

[Joolsplus2]

My slightly older, slightly bigger 8 yo ds LOVES his Parkway...he's got a few years left in a booster, too, and has heaps of growing room in his PW. He IS a lot more comfortable when I give him a small plastic stepstool to rest his feet on, so he has one, and that's fine (otherwise he puts his legs up on the seat cushion, knees in his nose, lol).
I say, go for it...you can hand it down later, anyway, so no money will be wasted.

:)
Julie CPS Tech and mom to 2 in seats
http://www.cpsafety.com/articles/RFAlbum/SarahMA.aspx