I washed my Black roadster this morning to remove dust. I used a commercial car wash. I employed only the spot free rinse. Now I wait till it dries to see if it is spot free. Gary I checked it and very little spotting. The car wash uses processed city water that has little mineral content. I won't drink it. I drink my well water to get the magnesium, iron and calcium. No mercury, flourine or chlorine.

 

I have well water and the area where I live has very hard water. If I wash my car I get spots before I even have a chance to dry with a towel. I need to wax the car every time I wash it by hand just to get them out. It is really bad! And my car is black like yours so the water spots are very noticeable.

The spot free car rinse at the commercial car wash works great! I don't know if they use chemicals or if they have filters that really soften the water. Not sure if this is good for the paint.... but I will tell you it works wonders! I wish I had a filter system for my hose outside my home. I know there are systems that exist but just not sure how good they are.

 

These work pretty well.

For the price.

Amazon.com: Mr. Clean AutoDry Car Wash System Starter Kit: Automotive

http://www0.epinions.com/Mr_Clean_Au...ar_Wash_System

One question:

on your final rinse, do you remove the hose-end sprayer and just use a high-flow/low pressure stream to rinse down the car? If you have a decent wax in place, it should just "sheet" off of the surface, leaving very little spotting or pooling.

 

Back in the 70s I worked the evening shift at a laboratory & had a new TR7.....I would take home 10 gallons of distilled H2O (we had our own still) .....nothing better for spot free rinse that pure distilled H2O.

 

I save up the water from our dehumidifier. After doing a quick wipe off with a "proper" towel, I go back over the whole car with another towel that's been soaking in the "saved" water.
We have a well also.