We had a Chevy Equinox and could fit all 3 kids in the back seat....however, it was very cramped and while the doors closed, they would push against the seats. Not my idea of safety.
So, we bought an Expedition. It has plenty of room to fit all 3 kids, has a 3rd row bench if needed and no one is pressed up against a door.
I would say to take your seats and visit the car lots and install them on the cars you are interested in and see if they fit. It's not safe if all the seats are smashed together or you have to slam the door hard enough to get it to latch because it presses against the seat.