My front roof vent lid took a hike for the second time since I've owned my TC. It vibrates open while driving in spite of being tightened down and then shakes itself to pieces. This one is most like...
I use the commercial covers as well, but then, it rains a lot in this area. If those are too high, maybe adding a soft gasket might help. You could also add a clip of some sort to hold it down.