Elonheater32:
Are you washing with well-water from your property/house or are you using a municipal-sourced (water utility) water?
Either one could have hard-water (IE, mineral) issues. Even "treated/softened" water may still be a problem, depending on how much salt is required for a `softener".
I have neither a softener or a water treatment system and use a municipal-sources water supply (Green Bay Wisconsin draws its water from Lake Michigan) so it still has its problem with a some amount of limestone (calcium) in it. My 2-bucket wash is usually done in the early morning or late evening for three reasons:
1) Less wind and bugs flying around, hence less debris gets blown on a washed vehicle;
2) it is cooler temperature wise, so there is less evaporation of sprayed rinse water, the main cause of water-spotting
2) I can wash in the shade of a building (my garage) . I never wash in direct sunlight, unless it is below 40°F (rare Wisconsin winter outdoor washes!)
If it is a windy day or the residential neighbors are cutting the lawn grass, I try to avoid washing a vehicle (another reason I wash in the morning; no one cuts their lawn at 6:00 AM)
I also use a leaf blower to remove the excess rinse water as quickly as possible (NOT a good thing, though, at 6:30 AM in a residential area!) and then dry what is left with a pluffle-type microfiber drying towel. I wash the exterior top and side panels first, then dry those, and THEN do the wheels/rims separately. This methodology avoids letting rinse water sit on those panels too long and evaporate during the time it takes for cleaning the wheel well/tires/rims. if it is a colder, damp day, I may clean the wheels before drying after a rinse, but that is rare occasion.
Another suggest: buy distilled water and use that for your 2-bucket wash. You can "rinse" with it by using a separate wash media, like a microfiber noodle pad, and wipe with clean distilled water, but you do not have the benefit of pressurized water. An alternative suggestion is to buy a plastic pressurized insecticide garden sprayer and dedicate that for use with distilled water for your rinsing, kind of like a "poor man`s " pressure washer.