Maybe you are just reading those who tell you what you want to hear. In your first post, you said you were not aware you were speeding. What does that mean exactly? That the speed you were clocked at was correct, but the speed limit on that part of the road was 100? Or are you saying that you were not doing that speed, but that the Police radar was wrong, or they were corrupt.
OK, I see you now say you overtook a police car. And if the Police Car was travelling at the speed limit, then how can you say you are sure you weren't speeding. The very fact you overtook a police car is enough for the court!
If you had just gone through a roundabout there is no way the road speed was 100.
What speed do you think you were doing. I dont think you have told us.
No, you said you are not really sure. So how can you contest? Or what exactly, are you contesting?