it does look like a glow plug symbol to me, but it's down in the manual as " pre-ignition of diesel engine" if it's steady, or "Fault in engine management" if it flashes, which sounds even worse!
Still under warranty, so I suppose I ought to get around to taking it in for checking. Trouble is it isn't on most of the time.
Hard to believe I'm the first person to get it! Car isn't chipped at all, and I was just doing a steady 75 on the motorway.