On my 2007 Mazda CX9 when I plug into the 3.5 mm aux, I was getting a static/hissing noise. I was able to bypass the problem by connecting a noise filter to the 3.5 mm aux jack. However, I decided to replaced my stock radio with an android headunit. With this I'm getting that same static/Hissing noise thru bluetooth and pretty much all sources(not sure if Im getting the noise in FM). Youd clearly hear the static noise when the music volume is very low or when you skip the song (dead-air between songs). When the vehicle is on the road and the volume of the music is normal to high, you won't notice/hear the static noise. When you are typing on the screen, where you have that typing key sound, you can hear the static noise. However, when you pause/stop your music, typing or anything that requires sound, you'll have the static noise for around 3 seconds then it will go away. Ive tried installing a noise filter at the back of the android head unit, but it didnt work. Im no expert, but im thinking now if theres a problem with the oem audio noise filter at the tailgate or a problem with the oem amplifier. Any ideas and resolution would be much appreciated.