As per blkZ28Conv's suggestion I applied a coat of P21S over two coats of Souveran on my jet black BMW.
The P21S seems to add a little more reflection and pop to the paint while the Souveran makes the paint deeper and darker.
Here is a pic I took this morning.
Cheers,
My Black 7 Series
The P21S seems to add a little more reflection and pop to the paint while the Souveran makes the paint deeper and darker.

Here is a pic I took this morning.

Cheers,
My Black 7 Series