Cleaning Up Mud,
Sorry to bother you, but saw your post about giving a token for each wash for the vacs. Not sure what his will cost, but have you looked into Touch4Wash. You can do the same thing with loyalty points but then have a lot more tools to offer other options and revenue streams. touch4wash.com if you want to learn more. If not good luck with the install and let me know if I can be of any service.