Cleaning black cars is an art and a science. You have to love the washing process to maintain them. I stopped buying black cars (owned a bunch of them over time) as they are spectacular looking when clean, for about 15 minutes.
A few tips...use quality microfibers and lots of them. Follow the basics of multi bucket and top down washing on a cool car in the shade. I've used Griot's products for in between wash touch up (Speed Shine, etc) and the lubricants in them help avoid scratches. Lots of products out there from Chemical Guys, etc., that accomplish same. I use Iron X on wheels and am going to try Tuga based on my CQuartz guys reco.
Key rule: do not apply pressure when wiping (cars surfaces, counter tops, your body parts!)
Ceramic coating will help prevent swirls, scratches and "micro-scratches" that will kill your shine. You still need to be careful. I have all of my vehicles paint corrected and have CQuartz applied by a certified pro. There aren't many around as they have complete initial training and regular refresher programs to maintain certification (requires travel and time).
Also, invest in some rock guards if you don't have them and Z23 or Z26 brake pads are a godsend. Good luck and enjoy her when she's clean!