I've been to like 5 or 6 spas already but all are very discreet, i.e. back door. In fact, I went today...I wasn't planning on it but got a text from the owner telling me one of my former regulars was working. She hadn't worked in a few months so I figured why not.
It was a bit scary though, as I was leaving, I noticed a white Ford SUV in the parking lot and I as drove past it, sure enough it was a police car. Luckily for me, he must have been pre-occupied when I came out and didn't see me. Be careful out there...