My 2003 CLK 500 with 67K miles is shaking slightly when idle. I have replaced the engine mount, plugs and wires and the gaskets that connet the intake manifold to the engine. The shaking although minimal is still there.

What could this be?

 

You replaced both engine mounts? What about the trans mount?

 

Would a worn out trans mount cause the shake with the car in idle and Park?