Engine Shut Off Without Warning problems of the 2004 SAAB 95

I have owned a 2004 SAAB 9-5 sport combi wagon since 2006. Twice, over the last several years (2011, 2014), my husband and I have been on the highway and had an ignition switch incident where he was the driver and I was the passenger. In both incidents, I turned around to talk to my daughter (2011) and then daughters (2014) and inadvertently bumped the the key in the ignition with my knee. The ignition switch is located in the center of the car by the console. It only took a slight tap of my knee and my car shut off while going at speeds of 75-80 mph on the highway. Fortunately, both times my husband was able to put the car into neutral and get the car off to the side of the road.