The "breathing" thing goes back to old high solvent/low solid materials which haven't been used by the manufacturers since the late 70's.
Has been being legislated out of use since the mid 80's.
The material today is closer to "plastic". It is a polymer based material.
All the "breathing" was about was to allow the large amount of solvent to evaporate. The old paints faded, cracked, checked, died back, and were a real pain. The car care products back then were nothing but cheap waxes and lots of oils to create a "makeup"effect and clean the continually oxidizing paint film from the surface.
There are a lot of tech articles on
www.autoint.com under the Magazines Articles section, not your "enthusists" type of stuff, but for trade journals.
Then under the Tech Tips Section, are tons of photos and text regarding the new materials, how it is applied by the vehicle manufacturers etc.
You might wish to take a look.
This paint stuff just keeps a changing, am 57 and shot my first vehicle when I was 7.
Learn something new everyday.
So, I will put up the "happy bounce" icon, since I am still kicking.
:bounce