With only 1 or 2 kids, get anything you want that has a back seat and enough trunk/hatch space to store a stroller.
3 kids, same criteria, with the caveat that 3 carseats will fit in the back seat. It is possible, although very tight to do this in a 2006 Prius, IME.
4 or more kids, minivan/van/bus/Suburban/ etc. Or maybe a 6 passenger sedan, but those haven't been made in like 15yrs?
Wife had an 04 Pilot which she drove while having 0, 1, 2, and 3 kids. After 3rd kid, storage space was getting tight and a 15yrold wrecked and repaired Pilot with 272,000 miles on it was making me uncomfortable to be main family hauler. Replaced with a 2010 Odyssey with 175,000 miles. HUGE improvement in interior space. With all 8 seats up, cargo space was equivalent to that of the Pilot with only 5 of its 8 seats up. Also, Odyssey will take a full 4x8 sheet of plywood with all rear seats out. And has decent power while being nearly invisible to cops. MPG around 20. Only downside is tight engine compartment and sliding door issues.
For us just depends on what we are doing. It's me, my wife and 3 kids (9,5 and 9months). We switch between a Charger RT, Suburban and Chevy 2500
I came here to say Mazda 5, but it's already been said. But I'll say it again. And so will Mrs Monohue.
This came in shortly after she got her 5, a 150k-mile 2009 Sport (base) model we bought a while back. It was a dirt-cheap purchase with a few rough edges, but entirely presentable. Not perfect by any means. Plenty of power and room for what we do with it and the one preschooler we shuffle around. I don't find the lack of power sliders to be a big deal considering the manual doors can be opened or closed by a determined four-year-old. A little more room would be nice, but that would mean a bigger vehicle. This size works well for us. No rust because we're not in the rust belt. If something breaks, I can fix it.
It's probably all a moot point since you're looking at stuff that is probably at least a decade newer. Still, I am a fan.
Sliding doors are the best.
Kids come with a lot of accessories.
Some of the discoveries were unexpected:
1) 2 door golf was easier to put a baby in the back seat than my e36 m3 sedan (I could easily get in the back with baby) Rear facing seat in the e36 sucked.
2) forward facing baby seats fit 911s just fine
3) nothing beat the dodge minivan. Storing stuff in the stow and go floor was unbeatable. Even being able to 'walk' (crouch) from the front seat to the kids in the middle or back without getting out of the car: doesn't sound like a big deal until you pull over on a freezing cold night because bubs just tossed his bottle, or stuffed animal, or...
4) The Prius v almost beat the minivan. Heap of room, cheap to run. Best all around appliance that I've had.
5)e39 was pretty good, I liked it more than the e60. Both were roomy with big trunks.
6) Family hauler is a Prado now, basically a Lexus gx with fewer toys and a small 4 cylinder diesel. It's better for towing and 4wd drive activities, but doesn't touch (not even close) the minivan or even the prius v for practical family hauling. I need the towing and 4wd, so I keep it. But access to the very small third row seats isn't ideal, and there is little storage space when the third row is in use.
