peterscook

Two months ago my 2000 CLK430 threw a P0305 code (cylinder #5 misfire). I had the plugs and coil replaced and all was well. A few days ago it threw a P0304 code for cylinder #4, and of course the shop (very trustworthy, Mercedes-only place) s telling me they need to do the same work for #4. I also have the option of having all of the plugs changed at once

My question is: Aside from the plugs not having been changed in at least 50K miles (car is now at 170K), is there another underlying issue that might cause these failures to happen so close together?

Many thanks for your help,
Pete