All, many thanks for your replies, to answer your points:
To Andy, if I was facing a simple five or ten MPH over the limit I'd be looking at £100 and three points, it's been five years since I last had an NIP so I might even get a speed awareness option. But twenty five over the limit is more like six points and a means tested fine unless you're suggesting otherwise?
To Fuzzy, I don't have a picture but I hear that it's possible to get one along with the full GPS coordinates.
To Richard, no question I was in the thirty limit when pinged.
However, we've wandered off the question a bit, so.....
If I download an OS map I can see the boundary of the village, let's call it Little Whinging, I can even get GPS coordinates for where the village starts and finishes.
If for example there's a speeding offence on the motorway it simply says the speed and the name of the motorway but in my case the NIP not only states the name of the road but also where on the road the offence occurred i.e. 55 in a 30, A1234 Little Whinging.
My point is that where I was pinged is not in Little Whinging, it outside the boundary of the village which I can prove using GPS. Therefore the NIP is wrong but does it matter???