Just wanted to give a quick update. The C43 continues to be a lot of fun to drive, but after 9 months of C43 ownership, I lost count on the number of times I've had to drop the car off at the dealership. From a broken power trunk, persistent interior rattles, and a transmission that is in the process of being replaced (I have an E400 wagon loaner in the driveway as I type), it is clear Mercedes-Benz cut corners with regards to quality. While Mercedes vehicles are luxurious, it is unfortunate to say that they do not provide the luxury of a peace of mind.
As a side note, I got three tire flats in the 9 months that I've owned the C43. On the contrary, I didn't have a single flat tire during the five years that I've had the Volvo S60. Just a streak of bad luck?