Will a booster fit three-across in my back seat?

Width varies a lot. Reviewers flag narrow-friendly options like the Chicco GoFit and Graco TurboBooster 2.0 for three-across, while the UPPAbaby Alta V2 and bulkier all-in-ones are harder to triple up. The honest answer from specialist communities is to measure your back seat and, if possible, test the actual seats in your car before committing.