I don't like the 0-40 Mobil1 . I use Pentosin PentoSpeed 0w30 direct from Germany. It carries the proper MB 229.5 spec, as well as the BMW Longlife specs for more than 21,000 miles. I can feel the difference in my motor running it and cold starting is fantastic. I also get better mileage with it than Mobil1. The best price I have found is here: http://www.partsquick.com/ProductDetail.asp?i=382564
$31.87 for 5L (5.28Q) shipped to your door, tax free, free shipping. Buying in liters is nicer anyway because the oil specification for the car is 8L even. I syphon all the oil out through the dipstick tube and add exactly 8L. I don't even bother to check the dipstick because it's dead-on, every time. (My C32 doesn't even have a dipstick, it just has an o-ring'd cover for the tube.)

Also, for the record, Mobil1 was NOT the OEM oil in the SRT-6, and probably not in the N/A cars either. The original oil was green, so it was almost certainly the (up to 2005-06) German Castrol Syntec 0W30. The Mobil1 thing is an American market cross-promotion between MB and Mobil. As long as you pick a 229.5 oil you're just fine. Like I said, Pentosin PentoSpeed is the best IMO.

Lastly, I get my filters here:
http://www.germanfilters.com/c32-amg...1247_3165.html
This is the OEM Fleece filter supplied by the same company that MB uses. I have 2 cars using this filter, and so does my brother, so I buy in bulk, but the single and 4-pack pricing is decent too.