Will 17 inch rims fit on my husband's 2008 Ford Mustang?

I bought my husband 17 inch rims for his 2008 Ford Mustang and now I'm finding out that they apparently don't fit. The guy at the tire place said that he wouldn't have enough space in the wheel well to turn. I'm trying to figure out if this is true or not. He has the regular Mustang, not the GT. The rims have 10 holes on them and I was under the impression that made them universal. The box says they are 100mm and 114.3mm. Did I buy the wrong rims, where will these actually fit?

The Mustang is a 5x4.5" bolt circle, also called 5x114.3mm, so that is right. How wide are the wheels? 17" x XX" wide? Like 8" or 9" or even 10" wide should be okay. Now - The killer: Back spacing? The Mustang changed the body style to the current 'retro' look in '05, & changed the wheel back spacing also. So a wheel for an '04 Mustang may not work on a '05 Mustang because of the back spacing changes. Find out what the specs are on the wheels, then look-up 2008 Mustang wheels on e-bay. Find a factory wheel for sale & compare the specs.

One of the Mustang option is 17" wheel so no issue there. However there are other factors such as wheel offset and width when come to clearance issues.