I know for certain that the Mercedes C-Class has a cheap interior and is cheaply made.
Certainly not up to the quality of older models.
Yet people buy them anyway.
While I agree with you, that the interior of the C-Class in parts looks a bit cheap -- especially the center console --, I must strongly disagree with you saying they are cheaply made.
I'm saying this having just returned yesterday from a 600 km trip in the Mercedes C350 of my stepfather, which has 25.000 km on the odometer now and still feels like a bank vault. There are no creaks, no fizzes, no crackles even on the most worst of roads (although I must admit that our bad roads are still very good roads by Texan standards).
Also there has been nothing wrong with the car so far, except from a flattened battery due to my mother leaving the sidelights on, before they left for a holiday.
The only thing that is clearly better in higher models like the E-Class, is the noise insulation. There is a fair bit of wind noise in the C-Class. And of course the space in the back is limited (which is the reason why I drove and not my stepfather). Only entering the back is already an act worthy of a contortionist for people of my height and size.
I sometimes wonder, Spectre, if all of your non-Jaaaag-related assessments are really all based on firsthand experience, or if at least a part of them is just hearsay, because at times they contradict so much to what I and other people experienced...
By the way: The C300 doesn't exist here. Is that the same 272 HP engine we have in the C350 here?