I just purchase a 2003 Porsche Boxster for my wife who is turning 50 from a guy in Louiseville kentucky and drove it back to Canada, a 10 hour drive to where I live. I sent the car to my mechanic and asked him to change the oil and other fluids. When he went to start it after sitting in the cold shop overnight he notice a black puff of smoke coming out of the tail pipe. After a while the smoke went away. In addition when he was changing the oil filter he say metal shaving od the filter and the filter casing. Are these problems that I should be seriously concerned about? And if so what are the repairs you are recommending?