Just gotta care for it, The few times that I have brought my DGM in i put a post it on the cluster saying NO WASH, they will DESTROY the paint. Black is easy to take care of it doesnt matter what colour the vehicle is, its a matter of are you doing it right or not.
I use a 3 bucket wash setup, One for the wheels, One with soap and one with just water to rise the wash mitt in. I also use grit guards in the buckets. I dry the vehicle with a waffle weave towel mostly pat drying. Its important that you try to minimize your pressure on the vehicle when washing, never scrubbing, high filth areas you need to dip into the rinse bucket before carrying on etc.
I strongly recommend this, its $5 and has free shipping, this sponge is amazing, filth does not stick to it if used right you will not gain a swirl.
ZYMOL SPONGE 1pk