You need to talk to them first before telling the customer you will set up there.
I am setting up at a Golf Course/Country Club for the past week, and let me tell you.....IT IS GOOD MONEY.
Anyways, the guy that runs/owns the place, had me detail his car and wash his truck. I have been doing his friends' cars there too, but yesterday, he told me I can only set up there for another week. He said nothing against me or the business, he just wants everyone to not complain after a while.
Other than that, it has been VERY profitable for me. I am hoping I stirred up enough attention to keep busy around that area.