From the same source as the Wheeljacks and Mirages, is Prowl - so beware of future Prowl purchases, in and out of box. Unfortunately, there appears to only be one significant difference to the figure, which can be corrected with the placement of a sticker (probably packed with it), so no way yet of distinguishing them out of packaging.

From the Allspark forum,
http://www.allspark.com/content/view/3949/20/
things to look out for - 'no pre-applied "POLICE" sticker on the door, brighter grid lines, and the sun burst being too bright'

The complete comparison listing has been added to the KO TFs website here:
http://highendtfs.com/images/idguide/prowlidguide.jpg