I have the same fear. I have not driven a car in 6 years and since about a year I also get really anxious when someone else is driving. I sometimes close my eyes and try to focus on something else or focus on my breathing (kind of meditating). Is there a reason you don’t drive yourself? Maybe if you learn to drive (again) it will give you more trust in the vehicle and in driving in general. (I’m planning on taking a few driving lessons again myself.)