Just to add, unlike some other airlines that offer the chauffeur service (and i'm specifically thinking VS here) EK allow pax on the cheap consolidator/IT fares to use the service.

Also, the process does seem to have changed slightly in that the chauffeur company (last time I flew ex MAN, it was Tristar Cars) call you up to get all the details, as opposed to the airline, so if EK has told you you'll get the car, then i'd be tempted to think you will.

If you haven't heard from anyone by the evening before your flight, give EK another call (and post back what happens - would be interesting to know...)