I once lived for 6 months out of my car. It wasn’t bad once you get used to it. As you say, self contained, heat, air, electricity, internet from my phone.
I had a few different parking places to sleep to mix it up and move around. Picked safe, well lighted places where I didn’t bother anyone. And I never left a mess or peed or pooped outside. For showers I had a cheap gym membership.
I saved up w lot of money during that time and I gotta say part of me missed the simplicity and freefom of it.
Unfortunately, it doesn’t take many bad apples to spoil the bunch.
If your customers have to step over human excrement to get in to your business, you won’t be in business very long.
What did you eat?