Yeah, I planned this exact upgrade. I bought a fold and tumble Besttop seat. I have tried both configurations and can't see a way to keep either pair of just seats AND install the bench seat. Along with the seat, I think I would have to mount it on top of something to bring the bottom of it level with the wheel wells, otherwise the leg room is not very confortable. Maybe a sliding drawer, with some reinforcement on the top to mount the bench on? anyone have reco's for that?