You have a van right. Miles of room in the back, put it in the back or in the arch somewhere and get a head unit with a remote control? That way you can easily set the mood music whilst in the back (which you can even pick from the awesome selection that has been entered into the ipod competition)!
Those Custom Consoles that were around in the 90's were awesome for fitting headunits and UHF's into. I am sure if you were a bit cunning you could build a roof console that hardly anyone would notice in a van as well.