this is the weirdest thing, but i thought I might share it just in case someone know whats causing it or if someone else has the issue. Randomly my front left tweeter will start buzzing pretty loudly to the point where I would usually turn the radio off. A while back i figured out it seems like going over bumps or someone closing the front passenger door will cause it. I then figured out that hitting the unlock button on either the driver or passenger door makes it go away. I have no idea why, I am assuming there is some sort of a bad connection or interference somewhere possibly in the main plug from the door to the car but really it will more than likely be impossible to find and hitting unlock once every couple a weeks when it happens doesn't bother me. Hopefully this helps someone with a similiar issue or someone knows whats causing this in mine!

 

So the drivers side tweeter is the problem?

I would take both door panels off (very simple) and see if all your connections are tight. Not the culprit, but just to check for odd things. Next, need you to take off the passenger kick panel piece, which will expose the factory amp. Take a pic if you can, but basically look for any frayed wires or maybe if someone spliced into them earlier on and didn't put them back properly.