The problem is that some parking lots actually do have time limits and do tow. I don't want to run that risk. Also around here, the parking lots do not belong to the stores. The lots are part of big strip malls or shopping centers so one store manager does not technically have the ability to give permission when the parking lot belongs to some other private entity or town.

I do get your point that I could go to a single business with it's own private lot. That may be my only option, but I wanted to hear other strategies people have used.