The surface is extra smooth and just before the start line there is a "wet" area to pull a burnout in. Pulling the burnout will clean your tyres of crap for a better grip from the start line and is
supposed to put some heat in the tyre and give even more grip off the line. In reality unless you have proper drag tyres you only get the benefit of the cleaned tyres - every little helps! but it is hard trying to do a burnout from the off in a DSG.
In low temperature the strip can cool off and give the effect of greasiness like Ben mentions, which for bigger HP cars isn't good for the overall times. If it is near freezing conditions then times will be roughly half a second slower than a nice warm day equivalent - unless you light the tyres up from the start line and then you could be over a second slower!!