Originally Posted by jester_s1
There are two reasons not to do that. First is cost, since automotive clear coats don't usually come in pint cans. Second is weight. A base/clear finish is usually going to weigh more than a single coat finish. Of course, if you want a wet look glossy finish you'll have to do it that way, but most guys who cover with fabric don't. And, of course, there can be worries about paint compatibility as some solvents in auto clear coats can dissolve the latex paint underneath.
Cost is not a reason because the clear properly stored will last for years and can be used on many airplanes making it affordable in the long run. The weight is no heavier than Systems 3, Nelson, or Klasskote, in all cases if you want it light then knowledge and application is everything, and personally I have never seen automotive sprayed on urethane attack dry latex.
I did not include Krylon because it is just not a player in standing up short or long term to gas or fuel. As I also already mentioned the automotive clear can have a glossy, satin, or a flat finish just by adding the compound to your spray cup as you go. It is funny that full scale guys do their best to get rid of the cloth look and modelers just the opposite.