How many time have people changed out the white plastic washer EBC 8031 on their cars. Just had to put a third one on today.
They get so hot that the plastic sort of melts and slips out of the bellows and disables the CC.

 

mine had a metal pacman looking disk the was on the end of the rod in the rectangular prism

 

Like wise, mine looks different but keeps popping out of is bracket. Need to find a way to keep that sucker in place.

 

Hmm! I never knew it needed a washer. On both cars I have with that style cruise, the two metal tangs are bent in slightly to catch the rod.

 

Your car may well have had the same issue leading to it being left off. Should be there.
Part number EBC8031