medbusiness

Hi guys...any help would be greatly appreciated. My custom installer is going to put an Avic-D3 in my 2007 Saab Aero Convertible which has factory XM...no Onstar. Wanted to know if and how to use the OEM "Shark-fin" antenna on my trunk with the new Avic-D3 and new XMNavTraffic unit...the installer tells me he does not know if this can be done...I hope it can. Any help would be greatly appreciated!