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
2008 WK Laredo 4x4
RC 2.5" Lift, Bilstein HD, Monroe LL, 265/70/17 General Grabber AT2, JK Moabs, 1.25" spacers, K&N 57 Series, PW Mod,
DDM 5k HID, VLED 6K LED Fogs, Stillen Covers, 15% front tint, BA System, Infinity 3.5" dash, JL Audio 250/1 & StealthBox