Just came from the Napa store near by. They did not have any information on the type of oil filter I need for my 300C. I informed the person behide the counter that another store has a STP Filter S16 listed for it. Napa guy crossed referenced and gave me a Napa Gold filter. Can anyone tell me the model # for the Napa Gold Filter just to make sure. Also, I'll be using Mobil 1 5w-20 and wanted Mobil 1 oil filter but it's not listed but I read on this forum that Napa oil filter is pretty good, so I accepted it.