That's pretty much why I wanted to do a temp controlled fan. That way when it's sitting on my desk in free air (ie not getting all that hot) the fan's running slowly and quietly and when it's in the car (getting somewhat hotter) it's running faster to give more cooling effect. With the player embedded in the dash it can be almost as noisy as it wants to be without me actually being able to hear it.

When I eventually get round to building a docking station I'd like to duct the air out of the box. Ideally I'd like it to go out of the back but I'm not sure whether the fan would have enough power to push the air through a long duct. I expect I'll end up just venting directly through the top panel.