From 2007 the rule changed. The speedo is now no longer allowed to read a speed above what the vehicle is doing. It has to be a 'safe' reading. It is also 10% plus 4 km/h so the speedo could indicate 114 and you are doing 100. At 100 on the speedo you could be doing anything between 83 and 100. So if you are picked up for speeding in a car manufactured after 2007, you are in fact speeding.