DS1 will be going to summer camp this summer and for smaller field trips around town they drive the kids in vans (bigger trips are taken in buses). I'm thinking we should just get an inexpensive highback booster for him to use in the van for those days, since he's still using the Frontier (and Regent) in harness mode and I don't want to change it to booster mode and it's too heavy to carry around anyways. So what inexpensive booster would you recommend? He's 6 1/2 years old, 48" tall, and 52lbs. He rode in his Frontier in booster mode a few weeks ago for a school field trip and did well.