Hello friends, I decided for a long search and research for the two articles of LiquiMoly. I do not know if they are good but because these are very cheap I will try them out. Can still use the premium items. At Amazon there are some reviews, well… There are also articles about these products if you use Google. Liqui Moly 1535 paint cleaner, 600 ml and here: Liqui Moly 1534 Polishing & wax, 600 ml Here: Thanks now for your suggestions and tips.