I use distilled water to avoid the minerals our tap water contains. Many areas have decent quality tap water but around here it tests at 32 gpg hardness, which is three times what is considered hard water. The calcium deposits in tap water can foul the spray nozzles and leave spots on the paint.
No need for soap, vinegar acts as the cleaning agent. Google vinegar uses and you’ll find its pretty amazing stuff. It has multiple uses for household cleaning, works awesome as a weed killer, (better than Roundup) but is mild enough to be used as a common food ingredient. A cup of it is enough for in-vehicle mixing, but if I’m mixing up a gallon I’ll add two cups.
Jet-Dry is used to break the surface tension of the water for quicker drying and an added layer of prevention against spots.
I’ve been using this home brew for decades and it works well for me. Give it a try, it’s a cheap and easy life hack.