I'm into my sixth year on my 535D, and have owned all the other BMWs on my sig block below for at least seven if not more years. Never bought an extended warranty, never had a major repair bill (except my 84 325e, but that's another story).
I wouldn't worry about it. And in your case, if I thought there were a problem, I would not go to a dealer and have it diagnosed.
I wouldn't worry about it. And in your case, if I thought there were a problem, I would not go to a dealer and have it diagnosed.