My 2012 Audi A1 has developed a leak or leaks at the top of the windscreen. When it rains there is evidence of wetness on the roof lining above the driver seat and I have noticed the driver seat cover being damp. After a recent frosty night small amounts of water was running down the inside of the windscreen in the centre of the windscreen behind the rear view mirror. The seal may have deteriorated over the year, however the seal is hidden under the screen so I cannot check for any obvious deterioration or cracks. How can I have this repaired? I am based in London but cannot find any specialist and would appreciate your advice.