E320 shaking at idle

[benmack1]

95 E320, wagon 146K

All of a sudden today my wife says the car is shaking at idle at intersections. It is shaking in park or neutral noticeably, but much more so when in drive, stopped with brake applied. Don't notice much when driving. The motor seems to be idling OK, I don't seem to hear any missing or rough running. I did some searching but can't tell much. Seems to me like a motor mount but I am far from an expert and wanted some opinions.

FYI, harness is original and I've read a bit about coil packs and plugs, plug wires, MAF, OVP. No idea what the heck most of that is or where it is, but the motor seems to 'run' OK.

Thoughts of where to start (is there something obvious I could tell about either a broken motor mount or any of the above items?). I haven't had a change to dig around on it yet.