Nice MANN Filter.
I'd like to see a Used Oil Analysis on your c300 with your Pennzoil Platinum European 0W-40 oil. I had the viscosity drop a lot on my turbo SLK using Mobil 1 0W-40 Euro and am now trying Castrol 0W-40 Euro and will post the UOA on next change.
Nice ride that C300, then I see...