[ryushe]

So I found out how to pull the speaker; it was a lot easier than I thought it would be. Ordered a replacement one (beware: the price got bumped from 63 USD to around 110 USD - just for ONE tweeter!!!) and installed it, but it didn't make one bit of difference. Gave the new one back and reinstalled the old one as it didn't seem to matter one bit!
So, my question has changed.

The tweeter channel still acts up, but as I now have determined it's NOT the actual speaker but more seems to be the output going to the tweeter, I'm pretty much back at square one trying to figure it out.
I asked one of the mechanics at the dealer and they say it can be as simple as damp in the door or a snagged wire, or it might even be the amplifier itself, which would be a costly business! Where is the amplifier anyways? In the booth or behind the radio? It's tyhe top-hifi system with DSP.
How can I test for any of this without ripping the car apart? I can handle easy things, but I'm not overly technical enough to troubleshoot this.

Thanks!