Shakes, rattles, and rolls

When you're down to fixing individual rattles, it's pretty much whatever works best for that particular problem. Silicone and weatherstripping are two useful tools. Putting vibration damper on the back of plastic panels helps, as does using sheets of CCF to isolate them from the sheet metal. You just have to be creative.

Nothing will compensate for parts not being tight enough. If your license plate frame is still rattling, you have to find a way to mount it better. I threw mine away, put damper on the back of the plate and used a thick enough piece of foam to make it tight. I also removed the bumper cover and did quite a bit of sound deadening inside it and on the exposed surfaces of the car.

You can damp vibrations before they get to the rattling part, damp vibrations in the rattling parts themselves and isolate/immobilize the parts. Pretty much all you can do.

I used sound deadener on the back of my plate and worked for me.