I think I read a post by t walgamuth who suggested using wd-40 as a starting fluid. The vehicle that carries the actual lubricant in wd-40 is quite volatile, but nothing like ether. So, sounds as if one were in a jam, a shot of wd-40 in combination with the well maintained glow plug system will likely get it to start if it's going to start at all. I have a block heater in my 220d, which does wonder's.