I have a '97 Volvo GLT stationwagon and need to fit three boosters in the back for carpooling. I tried all my boosters in various combinations, but none would work until I found a now discontinued Fisher Price Safe Embrace booster on ebay. The Fisher Price booster works because there are no armrests that interfere with the other two boosters and it is a relatively narrow seat with mimimal side wings. It is a tight squeeze and buckling in the Fisher Price isn't easy, but it can be done.

Success! The Recaro Start, Fisher Price Safe Embrace booster and a Britax Bodyguard

Here is the Starriser Comfy between the Recaro Start (with body cushion) and the Britax Bodyguard. The Starriser Comfy is a narrow seat and fits easily, but the armrests don't make for easy buckling.

Recaro, Starriser Comfy and Bodyguard

The key to getting three seats to fit is to have seats that "mesh" together. Even though the Britax Wizard is a large convertible, it sits high on a small base which makes it easier to fit and buckle two relatively wide boosters either side.

Another option with a harnessed seat: the Graco TurboBooster, Britax Wizard and Britax Bodyguard.

Our newest seats: the Britax Parkway, the Britax Boulevard and a Pretty Paisley Bodyguard

The following pictures show how two boosters work with a rear facing covertible seat, the Britax Wizard. Interestingly, because of the configuration of the seat belts in the Volvo, I can only fit the wider/bulkier booster on the outboard driver's side. The Starriser Comfy, a very narrow compact booster fits easily in the outboard passenger position but neither The Recaro nor the Bodyguard are acceptable in that position.

Starriser Comfy, RF Wizard and Bodyguard

Starriser Comfy, RF Wizard and Recaro Start