Car Stall problems of the 2002 Cadillac SLS

On three separate occasions this year, most recently today (3/22/14), the engine on my 2003 (?) Cadillac Sls abruptly cut off, similar to the much-publicized recent failures on gm's 2003-11 compact cars. My car is no compact, but I'm wondering if it uses the same ignition components. In any event, we were lucky to avoid an accident. After the first incident, I referred the car to my trusted mechanic, and he could find nothing wrong. One further note: when the engine cut off today, only * key was in the ignition, so it was * a matter of the switch being "weighed down" by an overloaded key chain. I will take the car to my mechanic on Monday and suggest that a new ignition switch be installed. But all this should serve as a "heads up" warning to gm owners who drive non-compact gm cars.