Another person that has a truck gun!! Nope never had that experience as I Conceal Carry My Pistol regardless of the hours behind the wheel .
You need a better holster .
You need a better holster .
It never happened with the M&P.OP: Evidently you feel that this is a Glock problem. How is that?
Worth a try, though it is rather like shutting the barn door after the turtles have escaped.I cut off a piece of a a damaged bicycle inner tube & stretched it over the grip of my 23. Trimmed it up so inserting the mag and the mag release are not affected. It’s a simple mod & I like the way the gun feels. You might want to give it a try.