Well, I used Prima Amigo and UPGP yesterday for the first time. I applied Amigo with the PC and a grey finishing pad on speed 4. It was amazingly easy to use and left a very slick finish! It didn't take long at all for the Amigo to almost disappear, leaving only a slight bit to wipe off. Wiping it required almost no effort at all. It did seem to hide a few swirls, but nothing dramatic. However, I do believe it made the paint darker and I enjoyed that effect as my paint is straight black, no metallic flake.
Then, I tried UPGP. Despite all the warnings and my own experience with other WOWA products, I applied WAY too much. *D'oh!* I used one squirt per panel and that was big time overkill.
I waited until this morning (well over 12 hours) and went over it with Prima Slick QD, and it was very easy to remove, so not a huge deal. I put a second layer on this morning, much thinner, but I still bet I'll need to wipe some off tomorrow morning. This time, I used one squirt per two panels and it still seems to have gone on too thick.
If I get a chance I'll post a photo after this second layer has cured, but the weather may not cooperate tomorrow. After the QD wipe down, I was very impressed with the slickness. I don't know if it was Amigo, UPGP, or Slick (or all of them combined), but it was impressive, especially considering it's been almost a month since I clayed and polished. And the shine/wetness was excellent! To me, it seemed like a wetter/deeper look than I got with Zaino. However, the Amigo may have contributed to that. Regardless, I'm quite pleased.
I'm not sure if I'll go for the third layer of UPGP tomorrow or not. I'm fortunate that I'm off tomorrow but I do have to go to work at 6:30 Tuesday morning, so if I apply another layer and it requires any buffing, due to the cure time I would have to do it in the dark tomorrow night, which means I'd likely miss some. (The lighting in my garage is awful.)
Anyway, so far, so good! I really enjoy both products and am looking forward to seeing if UPGP will help with my water spotting problem! Thanks again to all for all of your recommendations and advice!