Put the post here because many people bucket wash their cars... Every time after bucket washing my car I'm pretty amazed at how much it shines and looks really good. The secret has been simple and only takes a bit more time ..... Finish the drying process with any type of spray wax and polishing cloth (type used for buffing off wax). I start drying* the roof with drying towel (waffle weave microfiber) to get drops up. Then mist spray wax over the roof, wipe it in, flip the cloth and finish. Once you get to the point where the cloth glides over the finish, you're done. I never get water spots, the finish is great and it puts some wax back onto the finish, triple benefit. * I use a cheap electric leaf blower to blow water out of all seams all over the car. Speeds drying process a bunch. ** Some times when trying to 'finish' the car only with drying towel, the finish would just smudge almost like a film of wax being smeared around. Not anymore, with the spray wax, it's easy to buff out the car.
Glad to see another car lover here I've put 3 layers of Zaino5 on my Prius, and I spray wax every time after I wash it. Most of the dust, pollen, and water flies right off at highway speed except for the small area under the wing and door. It sure makes it easier on the never ending battle with dust and water spots easier on a dark color car.
If you are not doing it already, I highly recommend the "two bucket" wash method. You use two 5 gallon buckets with grit guards. The grit guards allow dirt to settle to the bottom of the bucket while keeping your mitt, sponge of choice out of the dirt. One bucket is for your soap and the other is for rinse the applicator. After I bought my car, I did a full exterior detail which included: Stripping the dealer applied wax Decontamination with Iron-X followed by a clay bar Cleaning and sealant with Duragloss 501/601 followed be Duragloss 105/601 Protective wax of Collinite 845 I used a Porter Cable 7424 polisher and the car looks superb! I also touch up with Duragloss Aquawax every so often. Even after a winter of dirt, salt and less frequent winter washes, the water and dirt just rolls off. I also use a leaf blower to get the water off the car. I follow up with a waffle weave to catch what's left.
Been using two 5 gallon buckets with grit guards. Dale Hardware buckets happened to fit the guards perfectly. Also have bright colored microfiber mitts to see dirt show up on it after a wipe. If dirt shows up, turn the mitt (no thumb mitt), wipe and look at mitt, etc... other day used a 3rd bucket (another rinse bucket). Might do that again to avoid refilling 2nd (rinse) bucket during washing.
I think you are accomplishing what a detailing spray application does without the extra step. Good idea.
I think the spray waxes advertise 'Wax as You Dry'. There were some times when I would attempt to fully dry the car with what I think is a good drying towel*, but would end up with a non-dried film on finish, like a fog or condensation on glasses. *$10 microfiber towel from Autozone type place Other times water spots would be left over after drying. I've been using the spray wax for probably over a year every time and I like it. I spend hardly any time drying a section with the towel. I'll wipe the whole side of the car quickly. Mist wax all along the side wipe it in, buff it out. Done. Next section.