Might be worth checking courtesy lights in the glove box and boot to see if they stay on when the lid / boot is shut?
I had a boot courtesy light causing battery drain on one of my older cars and took me a while to figure out.
Worth a go? Although I do not think this would drain the battery on a daily basis.
Anything that won't allow the CAN bus to go to sleep will drain the battery.
You can also test for battery drain using a multimeter:
Ignition off and key out of ignition.
Set multimeter to amps on DC unfused setting.
Remove positive battery cable.
Put black probe on the now loose positive cable and the red probe on the positive battery terminal.
The multimeter will now carry the current and show any current being drawn on the display.
WARNING: Do not test for prolonged periods as this will melt the multimeter, but ok for short tests to determine battery drain.
A good way to show this is to get someone to open the door while you monitor the current and you should see the amps shoot up as the interior light come on.
When you have a reading for what your drain is, start pulling fuses one by one until the drain goes away, you will then know which circuit is causing the drain.
Im not sure if pulling fuses wakes up the can gateway, invalidating the test, so hopefully someone can advise on that?
EDIT: Found this which show a technical service bulletin on how to monitor battery drain on golf / jetta:
http://forums.tdiclub.com/showthread.php?t=312511Hope this helps.
Jas