If this message is still displayed after a couple of ignition cycles, you have a safety-related issue that needs to be addressed at a dealership ASAP.
StabiliTrac compares the steering wheel position sensor against data from a yaw sensor behind the dash on the centerline. If the yaw sensor detects the car isn't lined up with information from the steering wheel, it will activate the ABS on the opposite side in an attempt to realign the car in the proper direction. This is great if you slide in the rain, but downright scary if you're driving in a straight line at highway speeds on wet pavement and it engages without warning. (Trust me, I know from experience.)
If the message persists, avoid staining your seat by disabling StabiliTrac. Press and hold the Traction Control Switch on the center console while in Park. The first DIC message displayed will be TRACTION OFF, followed by TRACTION/STABILITRAC OFF.
There is a Technical Service Bulletin (TSB) issued for a related fault your dealer should be aware of that can cause this message to appear. The cause is fretting of a connector on the underside of the steering column made worse over time by turning the steering wheel. A keeper is installed on the connector for increased integrity.
In short, have a dealer scan the car to isolate the fault. Post the cause here when you find out please.
I'm a new owner of the 2004 XLR. That did the same thing to me and my husband showed me how to fix it. I believe there is a button where my arm usually lays, (right arm) next to the roof retractor button and you have just leaned on it. So just press on it again and it should go off. I know I didn't explain it correctly because I don't know what that thing is that I lean my arm on.
The switch you're referring to is the one I mentioned, the Traction Control Switch. It disables/enables Traction Control and StabiliTrac. It doesn't place or remove a SERVICE STABILITRAC message on the DIC. That message is a safety-related fault warning.
Messages on the DIC can be cleared by pressing the RESET button on the lower/right side of the instrument cluster. This button only clears the display, not the reason for the message being displayed (ie: LOW FUEL, SERVICE STABILITRAC, etc.)