IMO the true "wet" look comes from two things; depth and shine. Again, all this is simply my opinion:
Anyone here been to
Crater Lake in Oregon? Ever notice the depth that you can actually see? It's that depth that creates the
DEEP blue look to the water and the sparkle from the sun bouncing off the waves can be mesmerizing. It's one of my favorite places in the US and I love taking the family out west.
Depth on paint is a high quality polishing that
removes any swirls or marks and a nice glaze to help fill in the microscopic marring created during polishing to even out the
reflection like a mirror and allow the human eye to see right through the clear coat and down to the actual color. It's especially impact with
dark colors.
The next step is a sealant to help create that
WOW! gloss and
shiny look. Sealants and coatings to me really are what create that shine and mesmerize people when looking at cars. Top that with something like a carnauba wax and you'll warm up the tones within the paint nicely.
Sounds like a lot of work but honestly, I've been doing this on dark colored cars for years and especially on black, I always get comments about how "wet" the car looks or how deep the paint appears to be vs other cars. My wife hates when people say something as it just reaffirms why I like to relax in what I call suburban dad fashion on an early Saturday morning washing a car before the sun rises high in the blue sky.
Product wise, there are lots. I love either Poor Boys Black Hole or Chem Guys Blacklight for a glaze. Menzerna Powerlock just happens to be what I use a lot as a sealant. Blackfire Crystal Seal really helps amplify things between sealing. I tend to top off those with a hybrid product like Collinite or Blackfire's Montan Hybrid wax/sealant. To me those combos really hit the mark.