I agree with asking the management before doing it. It's not a right to park on theri property and spend the night. It's a courtesy that is extended. Give them the courtesy and ask them first. Give the other thousands of people the courtesy to follow unwritten guidelines and not to ruin it with your self imposed "I can do what I want" rules, so that it will not be ruined for others.
While 99% of people know that people are sleeping in an RV overnight if sitting in a Walmart parking lot, try to make it inconspicuous as possible. If you can sleep in it without popping out beds (extensions) then that would probablty look better. Is there a sofa to sleep on? Sometiems people can do that. Not everyone can do that.
Just remember to think about others and imposement it could have. It's not all about you. (not speaking directly to the OP).
