Question Author
Thanks everyone for your replies.
In the end came up with the following:
Honda CRV, Nissan Xtrail 3 seats no good due to seat belt arrangement / middle seat shape.
large family cars (mondeo , passat ,saab 5, Mazda 6 etc) didn't try all of these, but generally the middle rear seat was a funny shape or had arm rests in the way, so the seats didnt sit securely.
Big mpvs (Ford Galaxy, etc) Just too big!
small mpvs- (Toyota verso, VW Touran, Mazda 5, Ford Cmax)
Mazda- middle seat really thin so really only carries 3 rows of 2 which is ok if you never need to take a pram.
Cmax, Verso and Touran all very good. Didn't look too much into the c max as they only come with 5 seats- the other 2 have 7 (the back 2 fold into the boot floor when not in use). A weekend at the grandparents means you can unload all your stuff and then go out in one car.
The Touran and Verso both had individually moveable seats so the child seats fit easily. Boot is quite large and you can also move all the seats forwards to make it bigger. You can even get a stroller in if you have all 7 seats in use.
In the end I went for the Toyota with a 2.2 diesel engine on a 56 plate. The VW dealer was not as helpful (even though I was trading in VW) and the Toyota was much quicker than the VW on the road.
I get about 35 - 40 mpg around town and about 55-60 mpg on the motorway.
It has 9 airbags and you can turn the front passenger one off.
Best of luck with your search. Dont forget all baby seats are different. We had Maxi cosi ones - 2 xps and a cabrio.