ALWAYS dispute the camera. Ask for the photos - You are entitled to. Check the timings and the road markings. Check it looks like you. Check the plate is clear. Check if it is even your car! (Has been known). Check the letter has been signed by the appropriate senior police officer. But best advice of all has been given already. Don't speed:-)

Out of interest. The 'new' style cameras that take your average speed over a mile - They take pics from the front right? How do they catch speeding motor cyclists? I quite fancy taking the old Honda Iron Horse for a spin round the M25 at 110. That is if ever you can go faster than 5mph on it;-)

Cheers

DtG