I've always been told not to wax fresh paint for a couple of months or so.

 

The solvents in new paint need to time to disapate through the clear coat. Trapping them in there with a wax can be potentially harmful. I recommend waiting atleast 90 - 120 days.

As for the best wax of a black G, I would have to say Pinnacle Souveran Paste Wax is by far the best product I have ever used on black. Its pricey but omg its stunning. Another great option (thats more affordabale) is the Poorboy's World Natty's Blue Paste Wax. It has a great deep shine. Like all carnauba waxes though these two products don't last super long so I typically apply a good sealant underneath them. My favorite sealants are the Menzerna FMJ, Klasse AIO is second and the Poorboy's World EX-P is a good value. Sealant + Carnauba Wax = great protection and deep shine