I was looking at replacing my engine cover bumper stops because the rubber bumpers are pretty hard. Well the drivers side just spins (the threaded insert in the cover must be spinning). Well anyway, the cover is very flexible and holds tight onto the bumpers but if it bounces all the vent covers make a buzzing sound. Not sure if I could hear that sound when driving but may look into a way to hold those vents tighter. The holders don't seem very tight.
Yes I'm finally doing work on the cosmetic areas of my car since I've designed all the electronic parts I can think of.