I'm still contemplating going the Rustoleum route on the outside of my truck...although I am going down to bare metal and epoxy first.
This guy mixed gloss with flat and sprayed and came up with the sheen I am looking for... as well as the color I want:
Rustloeum Paint job follow up (HAMB) The brown he came up with is awesome, and my PPG/Nason paint guy wants to charge me a fortune to match it. I want to lay down a really dark, warm Brown with a lot of red in it.