I lost it while changing my timing belt - I've since done about 2,000 miles.
After three weeks of a strange whining sound, I took the timing belt covers off, thinking the belt may be too tight. God only knows how the adaptor kept away from the belt and didn't rip it off.
Am I the luckiest DIY bodger on this forum?? (I got down on my knees and said a little prayer when I spotted it lurking in there)