In a message dated 6/24/2011 10:12:00 P.M. Eastern Daylight Time, hmlinc at sbcglobal.net writes: It was never used for anything and just blocked off. It disappeared altogether once the stock of '65 heaters was used up. Later, JR I was told it was for a rear window defogger option that never happened. Bob Hall Group Corvair Corvanatics CORSA