It does not make you feel very good. I lived in a car for about six months. Well, I alternated between the car and the woods. In the warmer months, I stayed in the woods with the car close by. As it got colder, I would use the car for heat by running it with the heater on maximum for as long as I could stand it, then cut it off and try to sleep until I could no longer take the cold. I would then repeat the process throughout the night. All in all, it was very taxing. The long nights gave me time to think about how to not ever be in the situation where I lived in my car again.
As far as showers go, I would use friends' showers, or in a pinch, use a fast food restaurants sink to "take a bath," or if all else failed, bathe in a creek. I don't recommend the latter.
You go to the bathroom in the woods. You can obtain toilet paper from the restaurants I mentioned before.
I look back on this time in my life with fondness. It has been one of the many factors in my life that have made me a better man.More questions on Life: