Care of an eight-year-old Audi A5 dark blue-metallic

Hi you guys, I wanted to hear your opinion. A month and a half ago I bought the car. The dealer had prepared the car shortly before; I don’t know what he did exactly. In addition, there is the newly painted bonnet due to rockfall. As a result, the rainwater is currently draining from the entire body including hood. Can I therefore assume that I am excluded from the care (polishing and growing) this year? How often would you generally polish and grow ? Is it enough for the winter? In addition, the winter looks like this: I live in an area where it rarely snows and gets moderately cold. Nevertheless, there is always plenty of salt scattered. However, the car disappears in the garage from the beginning of December and comes to the road maybe twice a week. I will wash the car with my hand as soon as I was outside and was scattered. Only how do you do it with the underfloor wash if you are exposed to the danger caused by the he Waschstraße caused paint damage in principle does not want to go into the Waschstraße? Is there a program that only includes underfloor washing?