My phase I (pre-facelift) C-class is silent (save for sodding great engine noise) - very well put together and zero undue noises/creaks/rattles.
It's not something I will put up with (having had my drivers seat replaced in my E92 for a creaking noise) so I would have had the car in if it were the case. Also worth considering, I've had my lower dash and centre console in bits for Di-Noc wrapping and reassembled and it still doesn't creak.
Perhaps the phase 2 (facelifted) cars look better (being based on the current E class) but perhaps the early cars were better screwed together...
Gone but not forgotten:
325i M Sport (E92), Black Sapphire, Coral Red Dakota, 19" 225's, Seat Heating, 6FL and de-badge
Replaced by 6.2 litres of AMG powered C class.