Not sure about the traction control as I dont have a 2005 or 2006 yet, but the ABS should be fine as it doesnt really care how different the rotation is, just that it can keep the brakes from locking up. On the traction control it will have room to fudge the numbers a little and to my understanding it takes the front and rear numbers seperately to determine traction, and not front to rears. I would think it wouldnt throw an error or anything with the difference or reset to compensate for the difference. It's not like they are too different in size anyways, but I'll leave the confirmationt o someone who has actually already done the change. Hopefully they can shed some light on the issue. I have used similar tire sizes, but not on a Mustang that had traction control.