This my absolute pet-hate, and it happens so frequently. Over the summer I started to pretend to take photos of people driving down the road illegally, until one of them stopped to have words!
Pleased to see that the CCTV car has been there a lot more recently, and hopefully if it keeps coming it will help make people think twice before trying it again. Definitely agree that a more permanent solution would be best.
Part of the problem is that it is such a wide, empty and welcoming road for people wanting to take the short cut. I wondered whether a relatively cheap solution would be to have some unrestricted/non-CPZ parking bays right at the top of Manor Mt, perhaps at an angle rather than parallel to the pavement, in order to restrict the road width a bit and introduce a bit more uncertainty for those considering the turn.