Wide rear seat

Hello, I am currently driving an MB Viano, which is a disaster in terms of processing and has to go before it mutates to the savings box. What comes after that? We have 3 children, 3+3+7, but do not want to drive around with a sharan. Either bus or car. So a combo. The problem with combos is the width of the rear seat. Volvo V70 and Mercedes E seem to have the widest and I could imagine that our child seats Concord Lift Evo PT fit on the seat. But I’m not sure. The seats are at the bottom 43cm wide, at the top 48cm. Does someone have experiences with 3 seats on the back bench or would someone be so nice to measure his bench, possibly also with indication of the belt position? Thank you for your answers Greeting Hartmut