I used Swissvax's wax and shampoo for 7 years
https://www.swissvax.us/merchant.mvc...de=MATTE-PAINT
Some use Dr Beasley's
https://www.drbeasleys.com/shop/exte...-car-care.html
I found it easier to maintain ceramic coated black sapphire metallic compared to frozen grey ... I didn't have any protective coating on my frozen grey other than Swissvax's wax. The frozen grey attracts more attention