Will AIO remove the old Klasse coatings or do I have to use a polish with my DA machine to accomplish that?
I would not use a polish to remove the AIO. I would use a strong concentration of soap, probably a double dose, spot clay the areas that need it. Which will prob be the front end and the bottom-most areas. Then simply do an IPA wipe down with 70% rubbing alcohol
. You can even dilute it down a bit more if you want. Put mixture in spray bottle. Spray surface and wipe with plush MF towel. This will give the AIO a nice squeaky clean surface to bond to. Then put car in garage over night and keep it out of any kind of moisture for 24 hours so the AIO can bond properly.
Which means keeping it out of morning and evening dew.
I would use 845 as the winter protection. One, maybe two coats if you want. You have to be careful about polishing it too much. Keeping it clean and protected is the main thing. There's only so much clear coat on the finish. Typically it's the thickness of a human hair starting out new.