The eninge on the 2006 - 2007 C230s is a bit different than the earlier models . . . So I thought I would post a DIY thread for changing the oil; which I did today
1) Warm the engine a bit so the oil will flow more readily.
2) With the front portion of the engine cover removed, the oil filter is located on the front of the engine, slightly to the driver's side.
3) I could not locate the drain plug, probably under the splash panels. So, I pumped the oil out (2006 model has a dipstick)
4) I replaced new filter and 3 O-rings and re-install the filter. I noticed that there is a paint mark on the filter cap, so you can use that to tighten it the same amount.
5) I filled the oil with with 8 qts (+/-) Mobil 1 0W-40. Turned ignition to on (but not start) for 10-15 seconds before starting engine (I believe there is an electric pump that will prime the new filter). Then, I started it and ran for a while to make sure everything was OK.
6) Now to Re-set the maintenance indicator . . .
-- Ignition to on (but not start)
-- Page dash display to odometer
-- Arrow down to Service Indicator
-- Press Reset Botton (left side of instrumentcluster) 6 seconds until is asks to reset
-- Press again for 3 seconds to reset.
-- The next maintenance interval should display (13000 miles)
That's it, piece of cake.