WhiteDevil828

I have had this humming or buzzing issue in my 07 Nav C6 and it is very confusing Has enyone ever experienced this? I purchased the car in September and did not notice the humming. The weather was still warm at the time. As the weather became progressively colder I started to notice a humming coming from the passanger door speaker. The colder it became the louder the humming became. As I was investigating the noise I noticed that it did not hum until the display on the nav came on (The nav display turns on approximately 3 seconds after the car is started). The humming could be heard with the radio on or off. Also when I pulled down on the latch for the vert top to lock it, the humming momentarily stopped. The humming also stops when I turn off the display on the nav (the radio is still on and playing). As the interior of the car warmed up or the weather became warmer the volume of the humming became lower and eventually disappeared. Again, the sound only comes from the passanger door speaker, all other speakers are silent. I recently swapped the driver door speaker with the passenger door speaker and the humming continued on the passenger side so that eliminated the possibility of it being a speaker amp issue. Any ideas for a solution to this perplexing problem? Thanks in advance.