I've pulled into a Wal-Mart parking to just sleep in a car for a few hours when I got sleepy on the road. It's perfectly acceptable; obviously don't leave a lot

I've pulled into a Wal-Mart parking to just sleep in a car for a few hours when I got sleepy on the road. It's perfectly acceptable; obviously don't leave a lot of trash or anything. Not sure DOT regs allow for this if you're traveling for work, but it's not uncommon for truck drivers to have a small bed explicitly for this.