Windshield Wiper part

[Mystic ZR-1]

Anyone have or know where I can get the retainer that
holds the w/washer tubing to the back side of the wiper arm?
It's (brittle) black plastic, about 7 inches long and snaps onto the backside of the arm
holding the tubing in place. It's not in my parts book, only the arm and blade
is shown there. I'm sure it's not ZR-1 specific. This piece was on and broke on the
other C4s I've had but never bothered to replace it. Attached is a not very good picture.
Thanks