I doubt you will get any scrubbing issues with that spec wheel and tyre. Had 18×8.5 +43 on an 07 sti and had slight scrubbing with 235 semi slicks. A standard guard roll would have sorted my issue however the 06-07 sti have flares on the back so you cant roll them like you can with a bug. Sorted it with a tiny bit of camber to begin with, which turned into more once i had a more track orientated alignment done.

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