I asked about this before and I thought I had solved the problem

When I hit 3k rpms, i hear an electrical buzzing noise coming from what sounds like below the shifter in the tranny
Last time I bought this up i had my stereo in aux mode and we concluded that was why because of the ground loop
Today on the way home I was listening to a CD and i noticed it buzzing around 3k again, a little louder than before

Any ideas what it is? Its a little concerning to hear it buzz constantly around 3k and I know its not like the old rx7s telling me to shift ha

 

Great little topic.
And Nice work--thank you for sharing- for me this makes perfect sense though.