Never seen this with a car but I can tell you the same approach works for boat paint and varnish work.
Another method involves what is called "roll and tip". You roll the paint on, then with a foam brush just drag the tip of the brush over the surface of the paint. Works best with two people as you need to keep a wet edge. I've seen boats that were painted this way and you'd swear it was sprayed.
Finish with a wet sand with 1500 grit paper and a final polish and the results are stunning.
"The music business is a cruel and shallow money trench, a long plastic
hallway where thieves and pimps run free, and good men die like dogs.
There's also a negative side."
--Hunter S. Thompson
Guitars: Dean Sweet Wood 00R, Martin D2R, Guild D60, Guild D35NT, Morgan Monroe M30, OS baritone Uke