Well as you can see, like other code issues, it's largely regional. You would do best to stop by and talk to the local inspector and simply ask what's required for a CO. Since garages are typically left un-finished, it will problably be somethnig along the lines of what the other guys have stated... fire rated walls between the gaage and the living areas, wiring, heat, insulation and sheetrock in the living areas. I have never had an instance where they cared about trim and paint. Many houses in my area were sold with unfinished 2nd floors and those houses had a CO when they were originally sold. I know it's hard to believe and sometimes I have my doubts, but the building department can really be a help sometimes.