Beware mate,
The MK1 has four drain holes!! The two at the front you can see and the two at the back you can't see. If the ones at the back rust out its a major job.
Water fills the inside of the car up because the water runs down behind the inside of the roof lining, behind the side rear interior panel and fills up the rear foot wells.
You can only see the rear holes by taking out the sunroof and looking between the skins with a torch. If you take the head lining out(which you don't want to do if you can help it) you can see if the rust has taken hold. On the end of the drain there is a tube connecting to a plastic pipe that runs down the rear wing inside the chassis and should let the water run out just in front of the rear wheels.
The rust detaches the metal and the plastic pipe drops down into no-mans land.
I sent my Lhasar green mk1 to the scrappy in the sky because of this. took me months looking for the leek till i found out the sunroof drained from the back as well as the front!!!
Should keep them clean with piano wire or net curtain hangers to keep them clean.
Domma..........