fatsea on "cars with enough space for twins?"

We're having twins in December and, frankly, my Audi TT won't cut it :-). We're starting to look at cars that might be suitable for our new situation. Initially we wanted a small SUV type car, like the VW Touareg or similar but now we're concerned that the trunks in those kinds of cars won't be big enough. We're looking at pre-owned cars so they have to be at least a couple of years on the market. Has anyone had the same dilemma and what did you end up getting?

Thanks!