I waxed it a week after I got it. You should do it as soon as possible really. You shouldn't run into any problems as the paint on cars today is usually 99% cured by the time it rolls off the line, and after a long trip from south korea, its all ready for a wax.
I went a bit crazy and also hit it with the clay bar and then waxed it. I figured it had already got 3 months of exposure before I picked it up. Used Mother's clay bar system and then their FX synwax with great results.