Hi, I am driving a 2013 320i Sport Auto. At 15000km I have noticed that both rear tyres are worn out badly in the middle part of the tyre. Took it to tiger wheel for an alignment check, they found that the alignment was out and could only adjust the toe. They advised me to take it to BMW for adjusting the camber. The service adviser at BMW told me that this happened due to uneven tyre pressure. The tyre pressure was always checked correctly and so far the car is driven on tarmac only. Anyway BMW did the alignment and I am closely watching further wear. What could be the cause of this? Any comments?