Presently, the F6, the D3 and some high-end lenses and specialty products (i.e. the SP/S3 reissues) are made at the Sendai plant in Japan. All other products are made at the Thailand plant.
All the D300 bodies made in Thailand prior to release and stockpiled had to pass back through Japan, where they got a firmware upgrade to the production version.

Hopefully someone here that has one will let you know.
All my Nikon's (F2, F4, N60, D100, D200) were made in Japan except the Nikon D65 which was made in Thailand.
References :
proFotog