Interesting post. A year ago I did 1/2 of roof of my black SUV with Meguiars Ultimate Liquid and 1/2 with Turtle Wax ICE Paste. To me, they both seemed to fall short of what I was expecting compared to the old days of using that "Orange Bottle" which I did put on the hood of the SUV.
Yeah, the Midlands of South Carolina summer sun can be brutal for 6 months of the year and none of them seemed to have met my expectations.
I was a bit surprised at the Orange Bottle, used to far and away exceed my expectations and still may have been a bit better but you cant get it on plastic and that is a major disadvantage.
Maybe because this is my first Black vehicle in a long time, throw in the SC sun and never lower than 90 degree daytime highs for quite a few months.
With the above said, all 3, Meguiars Ultimate, Turtle Wax ICE paste, that orange bottle (Nu Finish) outlasted Turtle Wax Spray wax by a wide margin.
Anyway, next I am going to try a bottle of Griots 3 in1 Ceramic which some people seem to swear by.
So when its time to wax again, I use a multitude of waxes and see if there is much difference.