I think the build quality has decreased in the past 15 or so years as they added to many "fru fru" type items that really aren't necessary. Just read all the posts about electronic gremlin issues , the main mistake these cars seem to have. Faulty red warning messages on the dash readouts when checked out were "ghosts" in the system, ELECTRONIC Seat controller unit malfunctions that keep current on even when not used draining batteries, tilt /telescopic wheel un-necessary and more areas for short circuits to happen., INTERNAL headlight wiring ( my car is halogen , not HID's) being cheesy and shorting out ( I thought they fixed this in the 90's") this one is happening to my 05 C230 right now with the insulation on the wires cracking completely off them. ( on a car with only 39,000 miles this issue is pathetic!!...plus MB has not offered to even make a repair kit to fix available on an issue they are well aware of) .. How about the rear window shades that you really don't need, another strain on the electrical system and possible area for shorts to occur. Too many wires running everywhere create a great chance to have many shorts and glitches.
Then you have the clear coat peeling issues on many of the body parts that is STILL HAPPENING even on newer cars with the better ceramic clear coat that they now use. For cars that cost the prices these do ,and for them to not address the issues and offer to fix with recall/TSB's , but instead brush them off is ridiculous.
Believe it or not I am not trashing the brand but their quality issues of late. IMO, I just think that the older models that had manual adjusting seats, no tilt wheel or no over-useage of electronics were far more reliable cars. I wish they still built them this way ( or at least they "option delete" on power accessories would be nice).. I always thought these cars were built rugged and reliable like a tank, which is why I bought mine.
I love my 05 C230 Kompressor even with the irritating glitches that happen frequently and have no intention of parting with it.......................Jon 05 C230 Kompressor