general problems of the 2007 Mercedes Benz E350

6/29/14 traveling when check engine light came on. Stopped and looked under hood, did not see anything out of the norm, drove it home. Drove a few days later to dealership. Found intake manifold faulty and cam adj maginet. Not repaired-$3000 quoted. Drove it home where it remains. Searches on internet shows this defect is under investigation. Also car rides rough; all four wheels are bent due to regular road wear and tear. Both these issues could have caused catastrophic consequences. I am not the first owner of this mb. Were mb aware of these defects and failed to inform me prior to purchasing the E350? the manufacturer needs to remedy these defects.