Car security system won't shut off using key in drivers side door lock.

Factory alarm is probably trashed. If you have a sun roof, what typically happens is the sun roof drain is plugged. This causes the galley of the sun roof to fill with water and it usually leaks down under front of headliner along window rail and into the stock alarm. Fries alarm. Or, it could be simply the harness assembly to your drivers door, specifically the connector, is oxidized and causes alarm not to shut off when inserting key. Or......it could be the micro switch inside door lock mechanism. Welcome to alien technology, ya gotta love to hate those Jetta's. I have one and wouldn't trade it for the world though!!!! Lol. As far as sun roof, get a air hose and blow out the drain in roof galley, it empties via a hose through the trunk to rear of car. Hope this helps!