I'm back in the land of Mk1 having purchased an estate for £600.  Very happy with it, it's running fiiiine of course, but it does have similar age related quirks to my last one - namely leaks, which are dicking about with the electrics! 

 

I believe it's the sunroof at fault, as there's no damp inside, but when the rain came recently it sent the doors doolally, it spent days locking and unlocking itself, and not letting humans in or out.  When I opened the boot, water GUSHED out of the wiper mechanism :/  The doors are now sane again more or less as I bought it a cover, which is fine for home but not ideal when at work!!! 

 

So, assuming it is the sunroof, what are my options? can they be fixed? can I do that myself? 

So far almost every problem with leaking sunroof has been clogged drain pipes.

 

See (used mine as an example): http://www.oemepc.com/skoda/part_single/catalog/sk/markt/CZ/modell/OCT/year/2000/drive_standart/202/hg_ug/877/subcategory/877030/part_id/2561537/lang/e

 

Part #2 is a hose draining the sunroof frame (#11) and there're 4 of those. If any one of them is clogged, the water will overflow to the inside, not to the drain as it should. Sunroof is never water tight so it's built in a way that it leaks in a controlled way, typically to sills (which have drain holes so no worries).

 

On paper simple to fix with piece of wire (2 meters or so, longer than pipe #2), but in practice I can't say much, haven't tried yet on Skoda. BMW (mine, old 7-series) had almost straight hoses, easy to clean.

Thanks for this, will give it a go!