The reason I'm asking is because I have a neighbor with a 2003 CLK430 vert with a V-8 engine and he's telling me he just paid over $800 for an oil change and spark plugs. I told him he got ripped off and he claims that a Mercedes HAS to have Mercedes oil and oil filters only, or the car will blow up. I told him Mobil 1 full synthetic oil meets the MB229.3 specs and their filters are top quality too and for $350 I could have hooked him up and made some very good money off him. He thinks I'm full of crap. As for the spark plugs, I'm thinking Denso Iridium Long Lifes, part # SK16PR-L11. About $12 per plug. What say you guys that have a Mercedes? Is there a special procedure for changing the plugs and oil in a Mercedes?