Cutting the inner lip on the back wheel wells.

Taking another look at it the thing I didn't mention earlier and should have is that you need to look at the wheel tub above that lip. To me it doesn't look like you'll have enough room even if you do roll the lip back. It might not rub on the lip but if there isn't good 1/2" to the wheel tub it will still rub there during cornering, body roll, people in the backseat etc. Looking at that picture further I'd say you probably need more backspace or a smaller tire if this is a street car.