There are a couple of ways you can help the hard water spot problem. One, of course, would be to wash your car using a hose connected to the water softener in the garage. This is what I do in Arizona, but I know your water is probably even harder there. Pending that, you can try this. Once you get the existing spots off, apply the usual Zaino #1 & #2 and whenever you bring your car back home from going out, just give it a quick light "spray and wipe" with the Z-6 in the spray bottle. Do the wheels too. This does two things. It will all but prevent you from having to "wash" your car ever again, unless it's real dirty, so no water spots. Also, you maintain the great look and your car will always look shiny.
PS>>>another tip: When washing your car, or any car, always do the wheels FIRST. Don't wet the whole car. The idea here is obvious. You won't have to spend time doing the wheels later while the water drops dry on the body. Hope this helps. pete