Guys, I have 2014 Fusion Hybrid Titanium. I am experiencing the same noise from the rear dash area as well just like the "blars" guy. Drove me nuts trying to figure it out for a whole month. Took everything out and padded everything and nothing worked. I finally discovered the cause of the "Geiger counter noise" I opened the trunk and pressing down on the rubber seal on the top trunk lip. It made that exact noise ......... it was the upper trunk lip rubber seal. It needed to be lubricated with armor all. When it dries out it rubs against itself and causes the noise as the car drives and the trunk floats up and down going over un-even roads. I armor all the crap out of it and now the noise is gone. SOOOO Happy!!!!!! I hope this helps you! Whenever it rained, the sound was gone because the water acted as a lubricant for the rubber seal so no noise. Silencer!
