One problem related to tire bulge has been reported for the 2012 Mercedes Benz GLK350. The most recently reported issues are listed below.
My 2012 mercedes cls 550 , with pirelli p zero tires,had a tire blowout June "12. Another tire blew out in Mar '13 on the Mar visit to the mercedes dealer (salisbury MD), two more tires had bulges, allegedly from potholes,and had to be replaced. I wrote pirelli of the problem with my obviously defective tires, and the reply was "we need to inspect the tires" fat chance, after the tires had long been disposed- I even had to pay a disposal charge.