This is a weird one. I just had the radio in my 2015 Xterra replaced. With the sound turned off, I now hear a "static" sound coming from the passenger side dash speaker. It is not an engine whine noise that changes pitch with engine rpm. The noise is only there while the vehicle is moving. When the truck stops, so does the noise. Any suggestions? I'd like to have some idea of what is happening before I bring it back to the dealership.