I used Zaino on previous vehicles I owned in particularly black ones.
It was common practice by Zaino users to build up layer upon layer of Zaino to really enhance the shine, i.e. one poster had over 65 coats of Zaino and is still counting..
Albiet this is over kill...however, I ended up with 11 coats just by applying a coat or two after my weekend wash.

The end resultwas as follows:
1) People claimed my car shined on cloudy days
2) I hit and scraped a rusty jagged square aluminum pole over a covered parking lot, while pulling out...it put a fist sized dent in my fender, but did nto scratch the paint! It just smudged the 11 coats of Zaino!

Checkout Zaino...

http://www.zainostore.com/

 

I've heard that stuff is great!!!

 

Yes, especially for a black vehicle!
I used it on my Black 350Z.
Since Hummers especially H1 and H2 are so big, it can be a pain to wash and wax...
But, if you take a weekend to do the preliminary stuff, and then maybe the next weekend to put several coats on, you wont have to wax...actually polish for a long time...
I believe Zaino claimed 1 year if the vehicle is outside, and 2 years inside...they have updated many of their products, so its probably longer.
Thats why I laugh when I see some dealers charging $300+ for something similar....Heck, I think I paid $100+ for what I thought was a years worth and it lasted 5!
And that was with almost 30 coats!

 

Zaino is all I use. Last a good long time. Easy on, easy off. Definetly worth a look and a try.

 

Zaino is great. Tons of compliments when I used it on my BMW.