I use a torque wrench to spec and they don't loosen.I use a nut driver and get them "fist tight." They have a tendency to loosen up and fall out, therefore use some blue Locktite (not red!) too.
Well, that's true - I only have 37,000 miles on mine so can't compete with yours. But still, one wouldn't think there would be a difference caused by mileage on a static part ...I have done that, and come back a year later for an oil change, and still missing one or two. You don't have near as many miles as I do, so maybe the screws and the spots they screw into are loosening up. I bought a 10-bag of replacements about 7 years ago. Expensive little items, for what they are.
If he stuck to the maintenance schedule, he would have removed them 10+ more times than you have. Things are getting squished and stretched.Well, that's true - I only have 37,000 miles on mine so can't compete with yours. But still, one wouldn't think there would be a difference caused by mileage on a static part ...