2011 Mustang wheels on a 2006?

The bullits may rub on 06 calipers. But if you do not get bullits.. then...don't worry about brakes.

But.. going to a larger size wheel on a V6, you may rub on the inner fender well. Turning wheel lock to wheel lock as in doing U Turns, etc.

In that case, you may need this:

Roush Mustang Steering Rack Stops (2005+) at AmericanMuscle.com - Free Shipping!

I just put 2010 wheels/tires (18") on my daughters 05' V6 yesterday. I do not rub anything.

I wouldn't let it worry you. "IF" you get inner wheel fender rub, the fix is $10 and 10 minutes of your time.