What is a wet coat?

A wet coat is a final heavier coat that looks wet after you put it on . It takes a bit of practice because there is a fine line between a wet coat and too much paint that would just end up running. You Usually mist on several light Coats 1st to build-up the color and give the wet coat something to stick to and then you put on a final wet coat to give a nice smooth glossy finish. You should put on the wet coat  before the mist Coats dry completely

What I tend to do with cars is progressively heavier coats. How this is accomplished depends too on what you are applying the paint with. In my case that is generally an airbrush where I have control over the paint flow rate by opening the nozzle more or less according to the paint amount I want. With spray cans it's more about distance from the surface and speed of passes per coat ( still available to the airbrush user as well). With brushes it's the amount of paint you load the brush with. And in any instance experience and practice produce the winner. In spray painting there is a balance between distance sprayed from and how fast you pass the spray over the car parts. If you slow down it gets wetter, speed up then dryer or more of a mist coat than really wet. Same with distance, further away dryer, closer in wetter or heavier. A direct cross reference to dryer and wetter coats are the terms lighter or heavier coats. You should be getting the picture in your mind about now. Dry vs wet is about less or more paint per pass. Yet with an airbrush it's more than that because you can put down a wet coat that is light by changing nozzles but that's off the general topic here for now.

So recapping in a general way. Slow down and move in closer for wetter coats. Move further away and speed up will generally make more of a mist coat or dryer coat. This concerns spray painting, obviously brush painting is another matter and an art form of it's own.

I use the same techniques as above.  I wouldn't really call what I do coats though.  I've become accustomed to just using my old Paasche H single-action, siphon feed airbrush, so my way of painting is based on that.  In my case, I would call my base coats passes, since I'm going back over the model from where I began right after I finish the first pass.  The first pass is further away and faster, with each pass getting progressively closer until I have an even, glossy finish.  After that cures for about 7 days (that is for using Model Master enamels) in my little dust-free chamber (an upside-down Gladware dish), then I do my version of a wet coat.  I make a paint mixture using the base color and Model Master thinner...a mixture that is mostly thinner.  I shoot that in quick, even, straight-line passes.  When that cures, and I'm afraid to touch it because it still looks like fresh, wet paint, then I know I have a good result.  Ultimately its going to come down to lots of experimentation and finding a technique that works best for you, but this is how I do mine.  Its not just good for car bodies, but also for the dreaded job of painting the insides of jet intakes.  It melts down the base coat that is grainy due to trying to paint the inside of a tube, and results in a smooth, glossy finish.

If you screw up and want to start over, there's always a bath in isopropyl alcohol that can take it back to being a clean slate.  I've had to resort to that many times while trying out new techniques

I consider a wet coat as one just about ready to run.  How do you know what it looks like just before it runs?  Practice. I believe the secret to a wet gloss coat is to practice for at least a half hour or so on scrap plastic rather than gaining experience ruining good plastic models.

A lot of excellent advice here and something I am getting into myself coming back to modelling and airbrushing.

One of the advantages of a wet coat (if you get it right) is that it shouldn’t need rubbing down much/at all.  I have learned to my irritation that if you don’t think the paint properly and get the variables right, you get a rough surface as the atomised paint dries before levelling....bugger. This said I have seen this on full sized aircraft so we can all get it wrong.

 I tend to use acrylic lacquer and am coming on. Dont forget that with a wet coat, a huge proportion of it is thinners, which will flatten out nicely, particularly if you have a retarder or leveller in it.

One thing I have done in the past is a final blast with thinners. This can save a slightly dusty finish by levelling the surface.

One day I will get it right

Happy xmas and new year all