I took my V in for service today at the local Cadillac dealer. My car has 16,xxx miles on it. I bought it with 15,500. They called me about an hour after I dropped it off and suggested the 15k mile service. They said it included oil change, fuel system cleaning? , and tire rotation. I said I just had an oil change at 15k. What is this fuel system cleaning? Maybe that wasnt the correct term, but it was something with the fuel system. thanks.