Has anyone rated Walmart parking lot experiences?

I have stayed at dozens of Walmarts. No way could I rate them. Once or twice there have been some noise or activity in the parking lot. That is rare and usually over with quickly. I would rate all my stays at least "good". I could not do excellent because there is never any water or dump station. Truck stops often provide both but typically there is also a lot of noise and constantly moving truck traffic.