I bought my car a few weeks ago from a non-Porsche dealer. They serviced it at a Saab dealer, replacing some brake pads and sensors (used all OEM Porsche parts), and they also did an oil change (no filter change as far as I can tell). The invoice lists 5W30 Oil, but what makes me wonder that the quart only costs $3.30. So, I'm wondering if they may have used non-synthetic oil. Should I get this changed as soon as possible? I don't want to risk damage to my engine because of the wrong oil.