Adding Sirius Satellite Radio. Antenna Question

I am trying to add a Sirius Satellite Radio to my 2013 Prius II manufactured June, 2013. I want to tie into the existing Sat antenna, if it exists. I do not see any signs of the antenna cable under the drivers seat. I have not looked in the center console yet, as the radio I ordered, SCC1 with interface (Isimple gateway), has not arrived yet. I took my Prius into the dealer today for its first service. I asked the dealer about the satellite antenna cable, and the service manager said the II did not have a sat cable. He pointed out that the antenna on the roof, was smaller on the II than for example on the IV, which was on the showroom floor. I am wondering if the difference in size is the addition of the sat antenna and the GPS antenna, or is he correct that there is no SAT antenna in the mount. Anyone out there with a 2013 that could confirm this? Anyone know the location of the sat antenna cable if it exists?

I have added a backup camera, Euro style mud flaps, and body side moldings to the car, so far, using the great information that I have read on this site. Keep the information flowing!

Thanks

 

I finally got around to installing the radio yesterday. I had pulled off the trim, and the Radio on Monday evening after work, but never located the factory antenna lead with the square connector on it. I looked under the driver seat, behind the radio, and in the dash area. I pulled the top glove box out, and looked under there. I looked through the opening, behind the gear shift lever, down into the center console but didn't see it there either. I used a flex camera to look up inside the dash, down into the console, and under the seat. If there is a factory antenna lead, they hid it well. Anyway, I just installed the little antenna that came with the radio (SXV200v1), to the right of the factory antenna, and ran the wire between the hatch, and the roof, and under the weather seal, inside and down the left side of the care behind the moldings. The radio works great. I signed up for a free 60 day free trial, and all is working well. It took three phone calls to Sirius to get me signed up. The first said I was eligible for a free trial, but I would have to call another number. The second said I was not eligible. I waited an hour, and called back, and that guy got me fixed up. It took two tried to get the radio to activate as I was in the garage, receiving channel 1, and apparently the signal in there was not strong enough to activate.