Been out of the car seat loop for a while, but need to get a highback belt positioning booster for carpooling. Plus, my multi-stage seats are expiring since I've had them so long. Looking at Diono (Cambria, Hip, Monterey), Graco (Highback TurboBooster w/Safety Surround and Affix w/Safety Surround) and, of course, Chicco Kid Fit. Want something with the "extra" side impact protection. Seems to be some out of stock items on manufacturer and store websites due to end of season/year. Anyone know anything about plans for 2018 models???