My kids are (a small) 9 and 4. They'll fit... damn it! ;-)
Besides, the car is mostly a daily commuter and fun toy for me, not the car we'll take on family driving vacations to Juno, Alaska. We've got the Honda Odyssey for that. On the other hand, if I'm being realistic, I should have at least the capability of hauling me and both kids to the store or something if my wife is away with the minivan. That's why the pure 2 seater would be... impractical.
But fun...