I decided to re-grease my shifter this afternoon and discovered that there were loose change within the center console next the e-brake (I hold change/cash in the "ashtray" after fast food runs). And all this time I was thinking it was the infamous clutch buzz on my AP1!

BTW, re-greasing the shifter made a HUGE difference -- I wish I've done this sooner. No more grinding from 1st to 2nd, too!