I've seen automotive paint used on the metal front doors of houses. Looks fabulous, and stays good-looking for many years.

Had a friend try to get some parts painted this way for a project he was working on and he found the problem was that the body shops either wouldn't look at it or they'd throw a ridiculous price at, since it represented an unknown, while they are already busy with predictable autobody work.

If I were you, I'd simply start calling some places and see if you can someone who is open to it and would quote at an acceptable price.

What you say is true. Listen to this: It's very expensive ( I was quoted about $200 per gallon) AND believe it or not I live in California and TODAY is the very last day to buy the paint! CALIFORNIA IS OUTLAWING IT AFTER 5:00 pm today. It just figures...tree huggers. (Sorry, hope you're not one)!