Quote Originally Posted by rokle View Post
Yes it has a sunroof but i really doubt that's the culprit. Im suspecting it is the tail light seals. I had s closer look today and the side with the water noise does seem to have a maligned tail light. Taking it to a workshop on sunday.
Thanks for the input everyone!
Could be in between the boot liner and the rear quarter panel. Can you open up the cover as if you were changing the globes in the tail lights?

Pretty sure my Golf has a drain plug in the spare wheel well too, maybe check there just in case?