OK...now I'm TERRIFIED of a repeat of the Sindelfingen-sickle-syndrome on my 240D.

I live in a condo building with no outside outlet provisions...is there some sort of PASSIVE heat retaining device I could use on, around, or over the engine.

As an aside...

I remember being snowed in at a rural motel during the Blizzard of '78. For three days a big diesel semi quarter of a mile away idled contentedly. Have heard of some MB 123 diesel owners trapped in unexpectedly frigid temps who chose to let their cars idle all night with no lasting ill effect.