"The Home Office approval states that they mustn't be used through glass. They work fine but are not certified to operate through glass. If they are then it's game over for the conviction. I have heard that mobile gatsos have been used from inside a van, again it is not certified to operate in this way."
Source: piston heads forum post
Does it mean that I will have a realistic prospect of beating them in court should the worst happen? And what if they say the windows were open!?? Surely my word won't be trusted

Is it possible that the fact that windows were closed would be seen on their video? Or would that be someone in log book?