I used to park my car across the street too. Until one time I came out and it was gone. I felt sick. Damn, somebody stole it, not surprising; brand new car, with a lot of stuff inside including my wallet. Just took some cash with me inside.
Then I noticed the signs about parking only for customers, bla bla bla, violators wil be towed, never paid attention to these signs before. Finally tracked down my car to impound lot and paid ransom for it, what a pirate business that is.
Thereafter parked at the paid parking lot of the building due east of AC, which had a parking attendant. Worth the few dollars.
But I stopped going to AC more than 5 years ago, I think. Maybe things are different now.
Also since then, usually take my wallet with me.