I don't have the mat cleaners at my car wash, but like you have been curious about them. My mind always thinks about the liability factor. If the machine malfunctions or jams and ruins their mats, just another thing for customers to complain about. And, I would probably be responsible for damages. I prefer the DIY model, where the customer washes and cleans their own mats. In the bays, we have 4 mat holders they can use to wash their mats. On the vacuum island, I have a pedestal Carpet Shampooer from Fragramatics.