Personally I think that if Citroen had considered these ducts anything but essential they'd have saved themselves a Franc or two and left them off- their penny-pinching attitude towards the 2cv in the disc-brake era is well known.

Me? I took mine off because they were rattling (astoundingly).

I cooked the brakes in the Scottish Highlands, I cooked the brakes in the Swiss Alps then I welded some sturdier brackets to the evil, tinny, rattly, hateful bastards and bolted them back in place.

Never had cooked brakes since.