Unless you are exposing the player to unusual amounts of heat (i.e., leaving it in the parked car on a hot summer day), you should not need a fan.

Another solution is to do what I am doing this summer. Ride a motorcycle. Since the empeg is left at home, it dosen't have to deal with me keeping it in the car at work this year. Last year, I did have several times where I had to cool the unit down before driving off, mainly when I forgot to leave my windows cracked.

(And yes, I know, pull the unit out of the dash normally. My car sits in a secured parking lot at work, so theft is not a concern.)