I have a 91 YJ I'm in the process of building up. I really would like it to look similar to Mac's YJ, except for a 3inch lift and a v8 under the hood...lol. Anyone have an idea on how they painted it?

i would say get a forrest green color try this link it has a good color of forrest green http://farm2.static.flickr.com/1368/992213...3aeb18a.jpg?v=0

Yeah, there's two ways to get the dull inconsistent look on Mac's Jeep. One is to use a whole lot of extra lacquer thinner with the paint. The other is to rattle can the thing.

I'm not sure how you would go about getting that look, but here's a close up of one of the jeeps used in the show, so you might get some idea from that.

There's also some more pictures in our Media Center (which I must redo in a larger size, some time).
Some of those pictures show the jeep to be more of a brown color, so another option might be to paint it brown and then attack it with a sander before putting your clear coat on.

And yet another option might be to contact the owner of this web site and ask them how they painted their model jeep. You might be able to apply their technique in a larger scale.