We've also found 7 fit pretty well but have only done this irregularly and on short trips with minimal gear.
Maybe modern car and house size, etc. is the pendulum swinging back a little too far after many of us being cramped as kids?
For example, for much of my youth our primary hunting/camping truck was a Mazda b2000 with no extra cab. My father, brother and I regularly logged hours of travel with me riding on the lid of the center console or in the back of the truck (with a camper shell/top). It wasn't all bad but I have a pretty distinct distaste for being cramped and uncomfortable now and don't want to subject my kids to it. Sitting on the narrow, hard console lid with my head bent over because the ceiling was too close got old on the 4-5 hour drives we did a few times a year in that thing! I don't know WTH my father was thinking but it was a different era in many ways and mini trucks were commonly overused in my experience. Closest that I get to that discomfort at this point is flying commercial and I dislike and minimize that activity.
Fortunately the 80 is as close to perfect for our family of 4 that I can imagine and my discomforts as a kid only add to my enjoyment of it.
