I have not tried to use electrostatic paint with the wet stuff, but i have worked a lot with hand and "robot" spray booths for powder coating.
And things dont have to be that gnarly before the powder dont reach where it should in enuff to secure a proper coating when baked.
Actually even somthing simple as a door made in metal ( firedoor ) need you to touch up some areas with the handheld gun even with 4 automatic guns on either side of the door in the booth.
And even more so when the metal frame for that door swing buy, it have even more nooks and crannys you have to cover by hand, this will be in the corners along what will be the top of the doorframe and the hinges for the door itself. But allso the bends in the metal in wich the seal will go and into wich the doow woll sit when closed, might seem like nothing as its just a 90 degree bend and it point strait towards the 4 robot guns, but still i advise to keep a close eye on it and give it a single once over with the handheld gun.
Actually all but the most simple things you have to watch out for powdercoating.
Now i do know wet painting is a lot smaller particles and as such they might be able to be drawn more into small places, then again looking at my own suzuki its easy for a skilled painter like myself to see a trained monkey must have paintes my car, sure as hell not somthing i would sign off on myself.
This is allso why i would never buy a fancy sports car, cuz the paintjob on them ??? damn
just as RAW as any other mass produced car in my eyes.
What rust proof a modern car is the whole chassis dip they get before paint, the paint itself is just there to seell the car and add a little more protection to the outside surfaces that do after all get a high degree of enviormental and mecanical wear to them.
They should paint cars to the highest maratime standarts, that way when the car is rusted avay you can still drive in a hull of paint in the shape your car once was