Is it possible? or would I have to buy a shaker from factory with the siruis built in?

 

Yes it is. My Mustang came with the stock radio and I wanted to install the factory sirius unit. Go to www.radiosandmore.com . This is for the Factory Ford Sirius Brain that plugs into the headunit. Sound quality is awesome. Their customer support is awesome. I hit the antenna under the speaker shelf and I get excellent reception.