WTH is this that just fell out of my /6?!

That could make sense too, since I also just flushed the blinkenlight fluid.

Hopefully you didn't use the cheap stuff. It's just colored water.
Try this:
http://kalecoauto.com/index.php?mai..._id=22&zenid=0c68cc2191800de07df83c848d582b8c

Also a good supplier of Quality Muffler Bearings!
http://kalecoauto.com/index.php?mai..._id=48&zenid=0c68cc2191800de07df83c848d582b8c