All the roof rails (part of the Premium package) are installed directly in the Japan factory. You can purchase MO without Premium Package, thus w/o roof rails. But you can not add roof rails as a separate option when purchasing a MO without prem package.
We tried, our dealer said their shop won't install it because it requires drilling and thus might've warranty issues later on.. So we bought our MO with Prem package just because of the rool rail!