I got pulled on the A417 a few years back coming back from Gloucster having seen my daughter. My stereo had been nicked out of my car and I got a bit bored and it was a new car so I thought i'd see what it could do. Anyways, after 10-15 mins of doing 120 down the dual carriageway I decided i'd had enough and backed off, only to see 2 flashing lghts in the mirror, they'd come down off the bridge above and had clocked me at 108, so had to go to Cirencester court.
Stood in the dock was very never racking, prosecution stands up 'PC blah blah blah was positioned on a bridge blah blah blah and was timed between two points doing an average of 108mph'.
They were gonna ban me for 3 months until I explained the situation with my daughter and then I got banned for 14 days and a £400 fine.
Also, i'd only just (1 month earlier) got 3 points for speeding over the severn bridge, I don't like heights so I raced over the bridge at just over a ton and the rozzers were sat at the bottom of the bridge, they clocked me at 89 which I was quite pleased about