I have a 2011 CTS I purchased on 2013. Like all my cars I purchased a bumper to number warranty. About 4 Months ago it started running very rough, according to the service dept. They cannot find a problem. Therefore there is nothing to fix. This morning I had the General manager on the phone and he told me that issue is a characteristic of the 2011, calling it normal and nothing to fix. I contacted a Attorney and was told to get that on paper, so when I called him back to put it paper he played stupid. I am an honest man and expect to deal with the same. Looking to hear from corporate.