There's some huge discrepancy re: Rockingham time. Here's the video of the M600 recorded time: http://youtu.be/v54CEAVEFWU
You can see the rest of Car magazine TT (for its 2009 Performance car of the year) here: http://www.youtube.com/user/tigrettin#g/u
The faster times (with the various cars driven for Autocar test) must've used a different configuration of the track. Rockingham UK (not the one in South Carolina, USA) is an oval track with an infield road course with various configurations: http://www.visordown.com/news/images/rockingham_track_layout.jpg