There was a figure published when Clarkson scribbled a brief (positive!) review a couple of months back. Might have been Sunday Times or similar but can't remember. The figure given there was about 214g/Km CO2 or similar. That's the only time I've seen something quoted as far as I can recall - no idea if it was right or is being re-tested / reassessed.
That would still be rather high but would be more consistent with other comments above. I don't think 384 g/Km is possible - that would mean about 16 mpg.
