gished: So I was one of the lucky ones who got a speeding ticket over the holidays doing between 104 and 110 km/h (106 to be exact)
Start off by asking to see their calibration records for the device they were using. But then if its a $30 fine just pay the thing, its not worth the effort. It sounds like you were speeding anyway.
http://www.delonixradar.com.au/new-zealand/