Speeding fine

[RepSpec]

hey all as the title suggests it this has to do with a speeding fine (or possible fine, but 99% sure).
i was driving this morning, 60kph area, heading towards an intersection in the right hand lane that then became 1 lane very quickly. was been closely followed by a guy, tailgating and such. thought i could get away from him, sped up to between 70-80 through the intersection and flash flash. the light was green.

i believe i was doing between 70 and 80kph. its my 2nd (possible) ticket but first for 5 years. i was having a look around today and found that i could challenge it but for speeds of less than 10kph over the limit.

what i would like to know is have people challenged at these speeds and gotten off and how did you go about the letter writing process. im not asking for dodgy ways people have, just asking if people have gotten off so i know if there is hope or not lol