Painting Your Airplane in the Hangar?

I just saw a beautiful Lancair 320 painted in the hangar. It looks
great until you get up close. The polyurethane paint is very glossy,
but there is dust particles and trash all over it. Even a few insects
in the middle of our NC winter.

Not to worry, says the painter, who runs an autobody repair shop. He
says he'll use 600 grit and water sand it all out and you'll never see
a bit of trash in the paint. Well, I hope. What do you think?

We had another builder here rent a booth in a fancy car painting shop,
and the paint job on his Zenair Zodiac looked flawless.

In Greenville, SC they used to transport plastic airplanes with the
wings off to a nice filtered booth at an auto paint shop down White
Horse Rd. and paint them there. The pressure air used for the spray
system was freeze-dried to take out water and other impurities. The
painter was a real pro who instructed in the auto body section at
Greenville Tech. The ships always came back to the hangar looking
great.

How's about it? Do you paint in the hangar or in a paint shop booth?
We have two more to do and want clean glossy finishes without flaws.
TIA.