I would assume its a 99 E300 turbodiesel....

This happened to a member here a couple of years ago. As I recall he had a problem with one glowplug - but I think the plug broke apart when he tried to remove it.

I've never had a problem removing a glow plug from any MB Diesel. I'm not sure if there is something about the OM606 turbo than produces extra carbon in the prechamber that causes the glow plug to "stick" in the head.

Most people on this forum don't have lots of experience with a car this new - maybe one of the professional techs can offer an opinion.

Tim