UPDATE -
In answer to a few questions. My Golf is an 05 and in Scotland. It also lived near to the sea. All factors why my car has had all the common corrosion areas. Oh, the car is totally undamaged and has never been damaged.
Well, I was told by VW the rear nearside arch corrosion was a warranty issue and they would repair however they refused a warranty claim/goodwill gesture for the tailgate. I wasn't happy with this so complained to VW customer care and opened a dispute.
Two months later, numerous phone calls, enquires with managers, warranties, bodyshop manager they agreed to repair the tailgate at their expense.
Both area's of corrosion have now been repaired.
So in total, my mk5 has had both front wings, rear nearside wing and tailgate painted due to corrosion. The car is currently sitting with only 26.5k on the clock.
What a saga to say the least.