So, my 66 plate Avant's aircon stopped working in the summer. Along with this the air conditioning was making what can only be described as a hollow blowing noise. Took it JCT600, they weighed the gas which indicated empty, but it held vacuum pressure. They filled it free of charge and said it was fine (hollow noise went away) and I took it back for a pressure check 4 weeks later. All good according to them. But the exact same issue has come back and my warranty expired in September. Is this one of those "tough luck" scenarios or has anybody had any success in follow up work post warranty? I'm wondering whether to take it back to Audi or go for a cheaper independent dealer.