My 9.5 yo son (65 lbs, 53") currently rides in a Britax Monarch. I think he's nearing the end of its life because he's almost out of shoulder-height room. I would like to keep him in a high-back booster for a while longer if possible (backless boosters still leave the seat belt across his neck). What is the highest-back booster with side-impact protection?
I can understand your concern. The Britax Frontier is a lot of $$$ for just booster use, but it is the tallest highback booster. Believe it or not, the $30 Cosco highback booster is also fairly tall, but at his size, I don't know he'd be comfortable in it.
What kind of car is he riding in? Even my 6 yr old fits the shoulder belt in most vehicles w/a backless booster, although we only have one as a spare for emergencies. We have the $13 Harmony literider from Walmart. Shoulder belt fit is fine.
Send us a picture if you can and we'll help you out as best we can.
henrietta