It's incredible how much noise that alternator pulley can make!
 

That clutched/freewheeling (is it viscous?) alternator pulley on the manual cars sure can make a lot of noise when it fails! It's crazy how bad it sounds once seized up. I guess maybe it's from the ball bearings tossing around inside it? My 986 has sounded like garbage at idle for a long time. It sounded like one of those rock tumblers you use to polish rocks. I finally got in there the other day to isolate the noise (I knew it wasn't internal and was fairly confident it wasn't from the clutch/bearing so I let it slide for a long time) and today got the replacement pulley on. She's quiet as a mouse now (aside from the Ti exhaust) and I'm no longer embarrassed at stop lights and parking lots haha.

You are a dare devil
Continuing to drive the car with all that disintegrating bearing noise going on right behind your ear.
When one of my ideal pulleys started to go, I order all three, stopped driving the car.
I was terrified it would seize, chew the belt apart and then be stranded

Well, it was seized up and acting like a non-clutched pulley, so basically a normal pulley like on the tiptronics.

I wasn't too concerned about catastrophic failure as I have a 3.2 S motor and transmission waiting to go in whenever I find the time or am forced to do the swap