ive been running a car detailing shop for years and that was the most overboard shit ive ever seen . as for your black car i do at least one black car a day and every customer is stunned how good they come up. theres course compound then theres light polishing compund to use to remove swirls and all in between.
ive you need to buff a car hard you only need 2!!!!!! course with a hard sponge and apply pressure using a watermist to not clump compound then go over with foam polishing pad glaze and a waffle pad, repeat if necessary. steam clean then wet polish with a resin polish such as "autoglym resin" then a wax polish.
re apply a wax polish every couple of months then resin a month after. if you apply resin polish to often it will build up and create a glazey look
. look at me carrying on lol