A motorist convicted for speeding on a motorway fitted with the ‘wrong shaped number’ signs has become the first to see his prosecution overturned.The Birmingham man, who does not wish to named, was let off the hook for allegedly breaking the speed limit between junctions seven to nine of the M42, despite making a guilty plea.At least 11,000 fixed penalties were issued to motorists breaking the variable speed limit between junctions seven and nine of the M42 last year alone.Matt Reynolds of legal specialist Just Motor Law, who took up the case is now appealing for potentially thousands drivers who may have been fined on stretches of the M6 and M42 to come forward  challenge fines and even bans.Police decided to scrap all pending prosecutions for speeding on parts of the M6 and M42 when it was revealed that Advanced Motorway Indicators fitted between 2006 and 2009 were technically illegal.This was because the font used to display variable speed limits on the electronic signs contravened the guidelines set out by the Department of Transport.Warwickshire Police also turned a blind eye to drivers caught last November, when the issue first came to light and the Secretary of State issued an ‘authorisation’ which allowed a rule change to ensure the signs were legal.Reynolds, who uncovered the error through a Freedom of Information request, said: “When my client was summoned to court for allegedly breaking the 40mph speed limit by more than 25mph, he faced losing everything.“The alleged speed at which he was travelling meant that an immediate ban could have been imposed, which would have left him incapable of carrying out his duties at work, which involved driving all over the country. This clearly would have had a horrendous affect on his ability to pay the mortgage and support his family.“Although my client didn’t think he had contravened the speed limit, he assumed that the police must be right and that he must be at fault, so pleaded guilty by post and received six points and fines and charges totalling £640.Although he escaped a ban, he was given six points which meant that his licence would be at risk for three years if any other offence occurred.”However, after hearing of the error, the client contacted Just Motor Law – which led to the decision being overturned.Mr Reynolds said: “If my client had known about the non-compliance of the speed camera numbers, then he would have realised he was in the right and would never have pleaded guilty originally.“He is grateful that the matter – which has proved extremely stressful - has been resolved, and is keen to alert other drivers in a similar position that they too may have been unfairly convicted.”