If you think about it. 15x7 0 offset sits flush with stock guards, flared guards, gives you another 20mm? So a 15x9 0 offset will be another 25.4mm wider each side. So you've just filled flared guards. And depending on offset. Ie: -15. You're wheel should be roughly(Gives or take a few mill, assuming the width of the wheel is actualy 9 inches) about 40.4mm (1.59 inches) wider on the outside face. So should clear flared guards by around about 20mm.
Don't hold me to anything I say. I'm usually wrong.
Edit: Wow, just pretty much answered my own question.
