In general, my black 2012 SLK350 is running great. Only one problem I've so far since day one is that if I start the engine when it's hot then a sound like "BOOM" can be heard at the exhaust pipes. Does anyone have seen the same problem? I brought the vehicle to the dealer twice, and they keep telling me that the "BOOM" sound happens on every new 2012 SLK350. Thanks for reading this.