Ok so here's the deal... I have an 84 Westy wolfsburg, I've noticed that when driving with the window down so that air flow moves thru the van I catch a strange funky smell.  The smell is not there when the windows are up and I don't notice it at any other time.  

 

Has anyone had a simular problem?  I haven't had a chance to take apart the AC in the rear to see there is something in there that may be causing this smell.  I'm guessing it's coming from the back???  Any feed back would be great, thanks.

Bob