Havn't got a large family (1 actually ), but I am a CM, with a Mazda Bongo, 8 seater, it has loads of room, can get a double and a single buggy in the boot, can store wellies and waterproofs under the seats, and can get 3 car seats accross the back and middle seats.
The only thing I wish I hyad done when I bought it, would have been to have the seat belts for the middle seats moved and the seats turned around so they were backing onto the front seats, saves pulling the middle seats forward to get into the back and means the Littlest ones would always have been reversed.