Thanks@Chris Bird appreciate the additional info. Have gaffered all the roof seals for now and will see how get on when the next heavy rains comes. Tried pouring some water down the gulley and came out through bonnet pull so pretty sure roof related and makes perfect sense with the weather conditions as you say. My father in law mechanic also recommended Tolley's independently yesterday 🙂 ! I know it's about volume of water in a short timeframe plus other factors you say but have you ruled out some narrowing of the drain hole with gunk, causing water to overflow down a-frame? Blowing air down etc. Otherwise it seems that roof replacement might be the only real solution as it's about stopping the flow into the drain holes. I'm not far from Surrey Sunroofs so might give them a buzz also. Fingers crossed we can get this sorted!
