I've had most of the common problems happen to me.
The plastic which is used to secure the movable interior components always seems to break off. It just takes time. Cup holder, glove box, console, mirror controls, etc.
The front driver side window fell into the car door. Seven months later, the passenger side window fell into the other door.
It's possible to unlock the doors manually, with the key, and still have the alarm on. Fun way to start the day. Another fun way is to wake up and not be able to open the trunk.
The bemoaned "shield" on the bottom front of the car should just be called a "bumper hook." Ramps, driveways, etc will catch your shield, dragging down the bumper. This slowly loosens and eventually breaks the tiny screws holding the bumper up... via plastic. Not worth keeping on.
The electrical system has been continuously problematic as well.
Over 4 years I've had many problems with my 2000 Jetta GLS.
However, when running well, the car was fuel-efficient. It ran quietly and handled well enough. It gets cramped in there quickly though.
Overall I do not recommend the 2000 Jetta GLS.