Just a couple comments on the the D I water systems. I've had the Invisible Chamois for years and it is not cheap. The amount of D I water available before a recharge is necessary will depend on the hardness of the water being used. I get about 10 wash jobs (rinse only) out of a tank and that's using it very sparingly. You check the condition of the water with a meter that tells you when you need to recharge. I have to send it back to the company UPS and they recharge and send it back for just over 100.00. So it cost me roughly 10.00 per bus rinse. Hey, it beats hand drying all that stainless.
There are other units out there that can be recharged by the owner with bags of resin and that's a better way to go. Just be sure to not only look at the cost to purchase the system, but consider the cost of the recharge as well. The companies always brag about getting so many gallons of D I water out of there systems per charge, but don't believe it.
And whatever you do, be sure to buy your next Coach from Steve!