I too have a black car and have a depth, gloss and pop of the flake that I'm very nearly entirely satisfied with
Mine is very nearly marr free, but to get it there, used the below products.
If extra prep is required :
PB SSR 2.5 on a polishing pad
Menzerna PO85RD on a finishing Pad
Planned normal regime :
Klasse AIO
Clearkote RMG on finishing pad
PB EX-P on finishing pad
PB Natty's blue by hand.

If extra prep is required :
PB SSR 2.5 on a polishing pad
Menzerna PO85RD on a finishing Pad
Planned normal regime :
Klasse AIO
Clearkote RMG on finishing pad
PB EX-P on finishing pad
PB Natty's blue by hand.