Interesting letter in yesterdays NZ Herald. Since, the writer posited, 24% of unlicensed cars are in Auckland, the owners should be prevented from purchasing petrol without a wof certificate ( also means the vehicle is licensed). Apparently he has spoken with the appropriate government department who think he is on to something. Why didn't one of them think of it? It must be fairly simple, given the forecourt technology of the average filling station, to make it work.