They are quite safe, and rigorously tested. Did you read their safety and certification page which details everything? They have full EU crash safety approval. That aside, what kind of booster seat are you using? Have you considered something like a new(ish) Skoda Superb, Ford Mondeo or even a Mazda 6 (albeit it being slightly more narrow than the other two). They will accommodate two ISOFIX rear facing baby seats plus an adult - or child on a booster cushion - in the middle without hassles. I know because I'm the same boat and really didn't want an MPV. I think I'd better get the snip quick, while my wife is still pregnant with number 3. We have two ISOFIX baby seats and the eldest sits in the middle. I've done this in the latest Mazda 6, Mondeo and Superb without problems. You can further mitigate any issues by selecting narrower car seats. Maxi Cosi and CuddleCo amongst others do slim seats which are full ISOFIX with all the safety stuff and five point harnesses, but are only in the mid to late 30s CM to early 40s CM wide. Most seats can be very much wider than that, and can thus impinge on the middle seat of the bench. With the Skoda Superb (new model, which is wider than the mk2) we find that the baby seats don't overlap their own section of the rear bench, meaning the middle seat is fully available plus some spare from the seats either side. Our 10 year old finds this more than adequate, and we've had adults in there too for an hour or so at a time without issue. Worth looking at if you really want to avoid seven seat hell. If not I can only suggest the S-Max 2.0 EcoBoost for at least a modicum of driving engagement while getting full sized seats.