koko_b_ware,
Unfortunately, I too have hard water. And when they "shock" the system, it gets even worse! I don't have the option of a water softener, so I've had to adapt and overcome.
Here are some things I do...
1) Use just slightly more soap. Keep in mind it is not the suds that clean or that are the most important. Lubrication is a key element, and car soaps I use (Gold Class and NXT) clean equally as well without as many suds.
2) Wash and dry in the shade! This is extremely important. As I wash a panel, I not only rinse it, but the ENTIRE car. This keeps it wet, and also cool so it doesn't dry as quick on its own.
3) If your hose is kept outside, run some water through it until the water coming out is cold. My hose sits in the sun, and the first minute or so of water is extremely hot. If I were to use this water, it would dry extremely quickly. I don't even rinse the car with it, let alone fill my wash bucket with it. Not to mention that it may contain even more minerals and gunk from just sitting in the hose for however long.
4) Dry very quickly. Master your drying technique. I personally use the sheeting method to rid the car of most water. Then a quickie with a waffle weave. Follow that with a leaf blower for cracks, handles, mirrors, TIRES, rims, wheel wells, etc. (my water will even spot tires, so they get blow dried). Then go around with the waffle weave again to get blown out water off the body panels. I seldom need to, but a QD with MF may be needed in spots if these steps weren't done quick enough. Or if you're so unfortunate to not have ANY shade to work in.
5) Own a white vehicle. They don't spot nearly as quick as a dark color!
I've been contemplating the Mr Clean thing, but have heard some bad reviews. If anyone has a good review of it, please post it. It gets exceptionally hot here in Louisiana, so any help in preventing spots easier than my current method would be appreciated.
Dave