My 205 coupe is rattle free, even the pano roof which concerned me before purchase (touches wood anyway). Considering I was looking at 2 year old RR Sports (SVRs) before I went MB, those owners would be over the moon if all they had to complain about was interior rattles.
Build quality is really subjective. In my mind my old Audi B5 A4 Quattro was built like a tank. My old BMW E39 5 series even more so, I still believe it had one of the best interior fit and finishes, period. And that’s even after owning an F90 5 series which was objectively better in every way.
All you can do is try several cars and make your own judgement. Owners have different experiences, different biases and many only use internet forums to complain about issues.
