we've had a fit for 6 years now. they rule. the Dart is a value-engineered Alfa Romeo Giuletta, for better and worse.
I have a story about the Fit. I'm a big, wide guy, and I have long legs. I test drove a Fit, twice, and barely fit into the car. I ended up buying a Scion xA and love the stupid little thing. The xA won't win any races, but I can eek out 38MPG if I drive like a grandma. My telescope easily fits into the xA, but will not fit in the Honda, despite the Fit being slightly larger. I'm happy that you like your Fit; hopefully they make more 5-door hatchbacks as that is my favorite car style. The next car is either going to be a Ford C-Max, Mazda 3 5-door or a Prius V. Hopefully the current car holds out for a few more years as the plan is to roll into a dealer at exactly 200K miles and get a new vehicle.
When we were looking, there were no xAs that hadn't been ridden hard and put away wet. It seemed like a nice little car but there weren't any specimens available that weren't beat to shit. Not so with the xD - lots of hard plastic in the wrong places. I was physically incapable of getting into the passenger seat without banging my knees on a dashboard that had no excuse to protrude as far as it did. We were looking for a used Fit but because Honda had brought them to the market so late, and discontinued them 9 months later, the delta between a used 08 and a new 09 was less than a thousand dollars. New it was. What's your scope? Back up in WA I've got a 10" Coulter f/4.5 Dobsonian and it will fit in a... Fit no problem. Of course, I can easily see the problems an equatorial mount would engender.
The xD is awful. The engine compartment is bigger, the passenger compartment is cramped, there is less cargo room, it is a heavier car, it gets less gas mileage than the car it replaced, the xA. The xA was originally a mini delivery van in Japan that they "youthed" up for the US market and targeted at first time car buyers. I got mine for about $12K and don't regret the purchase at all. As young first time buyers were the target of the car I'm not shocked that you saw so many used in bad shape. There is also an incredible after-market and tuner community around this and the xB. The xB is just something that I cannot see myself driving; if I need something like that I'll get a Mazda 5 minivan. The main telescope is a 14" Orion Dob that I use for myself and for outreach events. I also have an 80mm Stellarvue on an iOptron mount that I take images with (poorly). Both scopes, camping gear, laptops, batteries and supplies for a few days out in the middle of nowhere fit easily. Like I said, I'm gonna miss this little jerk when I have to trade it in.