I have developed a rough idle on my '00 W210. I thought it might be a fuel problem as I was putting regular unleaded the last 2-3 months, but have started using premium and it still idles rough. When you put it in neutral it smoothes out a bit.

I checked the archives and saw it could be the motor mounts, and nothing else.... the car has 60K miles....

I am going to check the motor mounts, after I check the archives. Any other ideas or start with that?

thanks