You've selected a very expensive wax. I've personally not used it, so I won't offer an opinion, except that there are plenty of waxes that cost a lot less.
I would suggest you consider a claybar (with quick detailer spray). That will make a huge difference in how clean your paint is. That will help you achieve a better shine with any wax (or sealant) you choose.
Also, if your black car has some scratches/flaws you will need a corrective polish. I used both Manzerna Intensive Polish (medium strength with a yellow pad) and also Zaino-PC (a finishing polish on a white pad).
Here's my thread with what I did on my '02 Basalt Black:
http://986forum.com/forums/showthread.php?t=13801&highlight=detailing
My car had a lot of visible micro-scratches before I started. I was able to remove nearly all of those scratches. I used Zaino sealant (not a wax) and I am still very satisfied with its longetivity -- 60 days later, the car still glows. Good luck.
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