I'm working on a graphic of a WWII airplane. So far I've been able to do
everything I need in Illustrator and it's almost done--my goal has been to
do it all in Illy and not have to migrate to Photoshop for things. One of
the last steps I need to accomplish is to do the exhaust stains behind the
engine. In a bitmap manipulation program I'd airbrush this for a soft,
feathered effect. Is there a way to do this in Illustrator?

Rock