Air vent knob btoken

[Oldboy racer]

Hi
Just noticed air vent know on central vents below screen is missing. Probably
Bly off for a while as hidden by left hand when driving. Don't remember breaking it. Is there an issue with these popping off.
Ca t find front part but vent piece left.
does whole unit need replaced ?
Read old posts about it being a problem

 

[Tell]

Hi
Just noticed air vent know on central vents below screen is missing. Probably
Bly off for a while as hidden by left hand when driving. Don't remember breaking it. Is there an issue with these popping off.
Ca t find front part but vent piece left.
does whole unit need replaced ?
Read old posts about it being a problem

In the early days people were breaking the air vents fins by vigorous cleaning. May the plastic is just brittle. You probably need those Erwin manuals and register as a sole trader .