My SLK had sat since before the pandemic, rarely starting and unlikely to have warmed up. The spark plugs I removed were of the newer NGK IFR6D10 Mercedes branded type, with an iridium central electrode.
One was not fully tightened, and I was keen to see the condition of them.
Did they need to be replaced? Let me know your thoughts.
As always, the risk is yours if you choose to work on cars. This isn’t an instruction guide.