1. Is it a past, current or future situation
Both. Technically I still live out of my car, although I haven't slept in a vehicle in almost 5 months. Current luck has me long-term house sitting, which is better than sleeping in a car, and they actually pay you!
2. How did you arrive at the decision to do it, and to stop (& the other questions)
Simple- my credit card. I've been out of school and working full-time for a few years now, but with limited earnings and my 10.9% interest rate, it was nearly impossible to pay down the balance. Every month I put all my extra money towards working down the balance, but it was so discouraging to go to a job I disliked just to watch my balance drop by a meager $100 or $200 a month (on a good month). In October 2012 my old living arrangement was coming to a close, and I took the plunge and moved into my station wagon (vehicle living is something I'd been at fascinated with since middle school). After a few months of cramped sleep (what 1 more inch would have done!!) I upgraded to a van, keeping my car as a commute vehicle. Midway through this experience, I discovered MMM and my savings rate really skyrocketed. To read my one year review look here:
https://forum.mrmoneymustache.com/journals/one-year-on/msg144288/#msg144288. Even that post is now a little dated, as in less than a year and a half I've been able to completely pay off my credit card (was $7k), cut my student loan by $5k, and save up almost $10k, all on a very modest income. It feels really nice.
Some things I learned? Well, pick a spot that's low profile. For me this meant finding a quite residential street where both sides of the road had someone's solid wooden fence. This way, no one would look out from their house and notice you or your vehicle. I'd typically arrive late and leave early. I did have a few awkward moments where my timing getting into the front of the vehicle wasn't the best, but hey, I just wouldn't sleep there the next night. I never had a run-in with law enforcement, but I did receive one nasty note from a homeowner (and on the first night I parked on their street!) that had apparently seen my vehicle nearby and assumed it was a live in. I kept the windows blacked out so no one could see in, which you obviously would never want. Another very important thing is organization. Not only is it key to not store many possessions, but keeping everything in a place that makes sense really helped me. After a few weeks I'd learned where the best spots to keep things were (that kept them both accessible and out of the way) and that really helped my comfort level. A big reason I made the choice to part with my rent was because it was relatively easy in my situation. Yes, living out of a car could be trying. But compared to many people in that situation I had it easy. My work had a gym with a shower, and my lovely girlfriend made sure I always had yummy fresh food to pack with me. These two things made the experience doable.
So do I miss it? Yes and no. I absolutely miss the freedom of always having my home right next to me. I love spontaneity and trips, so it's amazing to have a vehicle that's comfortable to stay in. My current station wagon is literally an inch too close for comfort, but it works for short stints. It might not be mustachian to the core, but owning a vehicle that can handle sleepovers is such a reassuring and amazing upgrade to my lifestyle, that I always plan on having a live-in ready car. It's been an amazing experience, one I truly wish more people got to enjoy.