The only 17" I know for sure that fit on an X are the new Nissan ones that go with the supercharged edition, but those are quite expensive right now. Do a search for the correct backspacing and offset of the rims before you shop, Xterra's specs aren't very common. I don't think anyone on this board has put 17" wheels on their X. You might want to keep an eye out on ebay for someone selling some off of a 2002 S/C version.