Is yours all sorted now ? I think mine is as I've had no water dripping of the heater unit since sealing around it under the scuttle panel despite steady rain since lunchtime. So just to recap on all my leaks
1. Water leak which ruined fr. sunroof motor, cured by resealing sunroof frame to roof ( drain tubes weren't blocked).
2. Leak in r/h top corner of the windscreen, staining the roof lining. Cured by resealing the r/h gutter & or sealing the top windscreen rubber.
3. Water leaking into the fr. passenger footwell which was coming down the inside of the A pillar from dashboard level. Cured by resealing the l/h gutter & resealing around the heater intake under the scuttle panel.
4. Water sloshing from the rear sunroof tray. Cured by unblocking the drain tubes, sunroof removed & resealed to body just for good measure.
5. Leak down inside of rear side windows, the heated ones in luggage area. Cured by resealing around frames.
I hope this may help others but it's certainly not a definitive list of all the water ingress problems on a D2, in fact I've probably only scratched the surface.