Re: Can you use existing Sirus antenna
Yes, you can reuse the stock Sirius antenna.
Im pretty sure on all '08-'10 models the Sirius unit is built into the stock radio.
This is direct from wkjeeps.com (pages 20-26 on the PDF for '08 + installs):
2008 82210940AB Gen 2.5, Sirius Satellite Radio Installation Kit: includes antenna, wiring harness and I-sheet. Requires radio with integrated satellite radio (RES, REQ, REN or RER). Installation instructions PDF
2014 - Altitude - Billet Silver
5k vled led fogs, 15% tint, Mopar Slush Mats & Cargo Mat, Blk Lock Nuts
Ready for install: Overland Mesh Inserts, DDM 5k HID Kit, JL 250/1
Next: 1.5" Bora Spacers, JL Stealth Box, SRT Springs, 2" Hitch