I've just bought a Volkswagen Touran automatic for £8000 with a 3-month parts and labour warranty. On way home from garage, I heard a knocking noise and got a quick check done on it in the morning. I was told it was a possible gearbox problem. I contacted the garage who said the car was checked by them and was fine when I bought i. After I said I would get a quote for repair, they seemed very wary and not helpful. Can you advise how I stand?