Germany's Auto Motor und Sport 'tweeted' a photo of the protruding appendage: https://pbs.twimg.com/media/BnlRwm9IUAEqWo2.jpg
Questionable aesthetics aside, attention then turned to whether the exhaust extension, also dubbed a 'megaphone' by the press, did indeed turn up the volume.
"So far no good news concerning the sound," reported German television RTL's Florian Koenig.
BBC correspondent Andrew Benson agreed that the initial reaction from fans was "almost totally negative".
The German journalist Bianca Garloff opined: "In my view, the new sound is even worse", while Sky's Rachel Brookes reported she heard "no audible difference".
Speed Week correspondent Mathias Brunner said the 'trumpet' was removed from Rosberg's car for the afternoon session.