2 children, up to 3 adults, do I need a MPV?

[fromheretomaternity]

I have a DS (2) and a second on the way. At the moment we have a renault clio which I think we are going to struggle to fit everything we need into. Can't work out if we just need a bigger 'normal' car or whether we need to go for an MPV.

we need:

to carry 3 adults comfortably (we often take my mother in law out in the car), plus 2 children in car seats

good sized book to fit buggy plus all our luggage when we go visiting grandparents or on holiday

Was looking at things like Ford S-Max and Vauxhall Zafira but maybe that is overkill for what we need??

We used to have a Zafira and I liked it a lot, it was nice and roomy and good to drive - the extra flip down seats were useful a few times but we didn't use them that much. They are ok for medium sized kids, but we changed to a Citroen Picasso recently - 2 adults, 3 kids (2 teens) to accomodate - the Zafira was too small inside for us all. I don't like to drive the Citroen as much (its huge) but it is fantastically roomy inside.
The Zafira is a tad small on the back seat - 2 proper seats and a sort of bridge seat in the middle.