Britax Frontier G1.1 Clicktight Harness-2-Booster Car Seat – Link 
This highly rated booster car seat has currently dropped to the lowest it’s ever been on Amazon, at only $264 w/free shipping!
Amazon also offers free returns on this item, if for any reason you may want to return it.
- Click tight installation system ensures that everyone can install the car seat securely and confidently by just buckling the seat belt
- Safe cell impact protection is an integrated system of safety components, including an impact absorbing base, tether and harness, an impact stabilizing steel frame, and complete side impact protection plus
- Safe cell complete side impact protection plus provides an advanced level of protection: a deep protective shell absorbs crash forces and shields your child from debris, and an energy-absorbing headrest keeps your child’s head and neck secure
- Quick-adjust, 9-position harness and 2-position buckle allows you to easily move the harness upward and buckle outward for a comfortable, secure fit as your child grows
- Front-adjust recline easily alters the seat angle for your child’s comfort