I second the +40 mm offset. The Nissan manual is 100% correct on that, and pretty much every aftermarket seller is wrong. Also, if it helps anyone, you can go up to 20" wheels (with appropriate tire sizing) and shift inboard about 1/2 inch before loosing acceptable strut clearance. Shift out is up to you and your paint job, but it won't be a clearance issue unless you go crazy.