We had an outlander that we could squeeze three seats into. But it was tight and uncomfortable.
We've just upgraded to a Pajero. I know not everyone's into 4WDs, but we live in the centre of the earth lol so it's kinda a necessity. Especially if we want to see DH who live in a remote community. We also have two anchor bolts in the third row, so could essentially hold 5 car seats....dunno where you'd put all the stuff that goes with them (the kids) though.

The car dealers kept trying to talk me into a prado, but if you do your research their back seats are narrower than my outlander was. For all my research we had to be looking at the big 4WDs (Landcruisers, Patrols etc), or otherwise an AWD that was large like a Kluger.

NRMA have a great site that gives you the exact dimensions of backseats. Not sure if I can post a link though.