Cadillac STS Forum - 2005 through 2012 Discussion, 08 STS stereo? in Past Cadillac Vehicle Discussion; Originally Posted by 1BadCadSTS
Where are you located?
The XM modules are vin locked and cannot be reflashed you'd have ...
There may be after-market add-in modules available for the base radio if you're just after XM, Bluetooth audio or a line-in. The OEM Nav is a long-way around to get that. While it may be the easiest way to get Nav, full functionality may not be a practical (cost effective) goal. Members advising trading for another STS to get desired features are making a valid point.
I'd say the way to start is to be sure what's most important to you and then evaluate the alternatives. Unfortunately, the STS wasn't sold/produced in large enough numbers for a lot of aftermarket solutions but members have found several. If all you want is XM, there are several ways to get there: (it was available on base & nav OEM's and then aftermatket options). If your heart is set on a full-blown system, I remember reading a post from a member who found a module that would let him store the base car settings without keeping the radio. (That may not help owners that want to replace their OEM nav but it solves that concern for you.)