One problem related to tire bulge has been reported for the 2009 Mercedes Benz C300. The most recently reported issues are listed below.
In 13 months and 9,000 miles, I have had to replace 3 continental extreme contact dws tires due to bulging sidewalls. One of those 3 was the first replacement on July 15, 2014. The first bulging sidewall happened 12 months after purchasing them.