Hi Walter,
please don't think I am being unsympathetic to your concerns as worrying about something really isn't worth it, you perhaps should sell the car and move on with something else, however, you say your car has been trouble free, so why worry ? Any issues surley would have presented themselves by now.
last year I bought my son an immaculate Saab 9-3 ttid4, it was fine until 4 months (came with 3 months warrantee) had passed and then developed a number of issues that cost me another 3k to keep it on the road, so I guess my message is unreliability can come with any car.