i puirchased this car a few weeks ago from a trader and when i drove it on the motorway for the fisrt time and wanted to check it out i noticed that the glow plug light started flashing. when i stop the car the glow plug light goes off and agian when i accelerate it comes back on flashing. another thing is that the exhaust gives out black smoke and the car sounds like a nd feels like it has got a cough when changing gears. if anyone could help then let me know what this could be. thanks