When the track is open to tourist driving sessions as it was in this video, the full main straight can not be driven due to safety reasons regarding cars entering and exiting the track combined with those going at full speed. So, this area is omitted. Laptimes are then measured from the "bridge" to the "gantry" areas. This means the laptime is artificially quicker than it should be although technically it still counts as a Nurburgring Nordschleife lap.
When we see laptimes listed often like those tested by German magazine Sport Auto (which are counted as industry testing) they omit a section by Grandstand 13 due to safety reasons regarding those entering/exiting the track. For this reason a Sport Auto laptime is only 12.8 miles long whereas the track is 12.944 miles long.
This is further complicated with the ring laptimes wars that have started as a result of Nissan pressing for times to showcase their vehicles performance. A flying laptime where one starts their full Nurburgring lap at full speed can only be done in closed sessions where others can not enter the track but this will artificially inflate a time as well. Now everyone is doing this to get the best time possible due to the importance being put on Nurburgring laptimes today as a measure of performance and means of comparison.
The vast majority of laps will be stopped slightly short for safety. With no standard set and evidence pretty much being a video posted of the lap taking place along with a press release there will be a bit of deviation. So, take a look at the video below and before you are ready to proclaim an M3 with suspension and tire upgrades faster than a Lexus LF-A, Mercedes McLaren SLR, or Corvette ZR-1 realize that based on the day the lap is run, weather, and if it is open to the public will change the times considerably. Still, a very impressive laptime going to show what the M3 with mild changes for the track is capable of.