Thankyou madnoel10, you may have solved my leak, sure enough the sunroof appeared to have excess water on the drivers side, I used a
6ft spring spiral drain cleaner from B&Q which I had bought for unblocking drains in the house. It fits exactly into the drain hole and you have to feed it in carefully almost all the 6ft. Word of caution- be careful it might seem to get stuck but twist it round till it frees itself. I hope this has solved my leak problem. Once again , thanks for the tip.