Hi
I had this problem on my Hartge , after it had suffered quite a heavy side impact.
The tyres would scrub the inside edge down to the cords in 2000 miles (fine before accident)
After numerous hours at the accident repairers , main dealers and arguements with the insurance co who all assured me nothing was wrong .
I then took it to Birds of Uxbridge Hartge UK who told me what was wrong in the car park just by looking at it .
Turned out to be the rear Subframe. Apparently they are designed to absorb impact and therefore twist if you looked down the line of the car from the front you could see the rear wheels were at different angles (hope this makes sense ?

)
Then if you put it up on a wheelfree lift the subframe didn't rest on the mounts and was clearly under tension .
After the subframe was changed by the insurance co everything was back to how it was pre accident
cheers
Andy
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88 E30 M3
51 E46 320 Se Touring
93 E36 325 TD Gone but still going !
83 E30 320i (alas long gone)
87 E30 Hartge 325i (gone but not forgott