For black, you might want to consider an actual polish, which the 3 stage doesn't have.

ClearKote Vanilla Moose Glaze (forget the name, it is a polish) would be best, as has some defect correctional ability by hand - which is how i presume you're working.

Topped with an actual glaze, ClearKote Red Moose Glaze, black looks amazing - you'll get a deep, rich shine. The glaze must be sealed; Poorboy's EX would be best for black by far - then you could wax as well if you wanted.

More than three stages, but it'll be a much, much better finish

Gareth