I don't understand mag mounts either. They are put on to keep from damaging the vehicle with a hole. My experience with mag mounts, although very limited, is that the mount scratches the paint and it comes loose and flies around when a big oncoming truck passes. Sometimes the air currents created by a truck are so severe that it shakes the car and that is when the mag mount goes flying.
I'm one of the biggest "drill those holes" advocates in the amateur radio and commercial / LMR radio field that there ever was. I have a magnetic mount horror story that happened to a friend of mine from a local radio club recently. This could have been a tragedy, but it wasn't, luckily for him.
This friend who I will call "Ken," was driving along a busy boulevard in a suburb of Chicago on a Sunday afternoon. As he was passing one of the local car dealers (which was closed as all car dealerships are on Sunday in Illinois), he noticed several of the large balloons which hold up strings of flags that are used for sales and promotions. Because it was Sunday, a few of the balloons were close to the ground and on the ground near the pavement. As Ken drove by, he noticed that one of the "strings" was immediately right in front of him. He continued to drive and was unable to stop. As a result, his car caught the string and in a matter of a second, snared the antenna on his roof that uses one of the "Hershey's Kisses" style magnet antenna mounts. The antenna somehow snapped off, and the mount was flown into his driver's side (open) window and smacked him in the side of the head. He said that he was dazed, and pulled over to the side of the road to see what happened. Until he actually got out of the car, and saw the remnants of the antenna (and mount inside his car), he realized what happened. A police officer was in the immediate area and approached "Ken" asking him if he was all right, and if he needed an ambulance. "Ken" said that he was OK, and declined medical assistance. When "Ken" told me this story on the air the next day, I said that I would be burning the telephone lines to the car dealership, informing them what happened, and how dangerous this was, but he said that he didn't need the aggravation and didn't want a confrontation (on the phone). So I guess this sort of just went away for "Ken."
This is a true story. Can you imagine if this would have happened if he was using a bigger antenna on the little "Hershey's Kiss" magnet mount? The whole contraption could have come through (the car window open or closed) and caused serious injuries or death.
