SpeedMunster, did you visit the alignment shops - what do they say? I suggest a computerised alignment shop. The manual ones that do alignment, ONLY aligns the front 2 wheels. The idea is that the front wheels take the majority of the load plus, as they are connected to the steering and chances are more that they can go out of alignment.
However, the computerised ones take into account the back wheel too. Can you post some pictures of how the wear and tear is? Is it inwards or outwards or just a lot of wear and tear both inwards and outwards?
I saw a few TBHPians have complained about rear tyres getting worn out, although i did not read all the responses. You can use the "Search this thread" functionality to search for alignment issues.
deep_bang, i have taken the car to various computerised alignment shops and they all had the same response... 'this is a problem with many indicas and they cannot rectify it'.
also, the wear is in the inner side of the wheels. what is surprising that both tyres are wearing out in a similar manner but visibly the wheels do not seem to have any bend towards the inside or outside.