Since this trial I dont think there's ever been another WRX used as a marked vehicle...
In late 1999, NSW Police purchased three Subaru WRX vehicles following a three month trial of the vehicles.
An external company initially certifi ed the speedometers in all three vehicles as accurate, meaning they could
be used for speed enforcement duties.
Shortly after the vehicles became operational, signifi cant errors in the accuracy of their speedometers
were identifi ed. This meant that highway patrol offi cers could not be confi dent of the accuracy of speed
infringement notices issued while driving these vehicles. Therefore, in recognition of this problem, directions
were issued by commanders and supervisors to remove these three vehicles from speed enforcement.
Despite these directions, some offi cers continued to use the vehicles to police speed limits and a number
of infringement notices were issued. When senior offi cers realised that the vehicles were still being used to
issue infringement notices, inquiries were undertaken to identify affected motorists.
This resulted in the refund of 530 fi nes.
NSW Police also commenced an investigation into the issues surrounding the use of the Subaru WRX as a
speed enforcement vehicle. This investigation was conducted by a task force known as ‘Operation Sibu’. My
Office is overseeing the conduct of Operation Sibu.
http://www.ombo.nsw.gov.au/publication/ ... pdf?id=120
So yeah as you can see they did 'test' the speedos, reading that whole PDF it would seem that they learnt from their mistakes and now test the vehicles at the start and end of their work life...