My wife has a factory installed XM unit in her '06 Honda Element. We cancelled the account last year once the free preview ran out, because we were already Sirius subscribers. She has a Starmate Replay in her Element. Can I call Sirius now and add that XM unit to my current Sirius account (which has 3 radios on it now), at $6.99/month? Or do I have to call XM and re-activate the account that was tied to that radio, at $12.95/month?