O.K.. You are all making a big deal out of something so simple. I live in a town that has a water hardness of 47 grains per gallon. I wash my car with softened water and yes it will leave little spots of sodium unless you dry with a chamois. For a completely spot free finish that I can let air dry, I simply fill a small Hudson sprayer(pump-up garden sprayer)(plastic is best) with R.O. water from my kitchen R.O. faucet. You could also use distilled water by the gallon from a local store. Then spray an even layer all over the car to displace the sodium laden water. By the way, you can wash the car with hard water and do the same with the R.O. or distilled water, but do so in the shade. This post may be a little late, but hopefully it will help others with extremely hard water.