Translate file is located in app/design/frontend/cartown/default/locale/en_US/translate.csv. Use it to translate custom strings into other languages.
For example you need to translate everything to French. Follow these steps:

  1. install French translation
  2. create app/design/frontend/cartown/default/locale/fr_FR/
  3. copy tranlate.csv to a new local folder
  4. edit with your favorite text editor
  5. switch store locale to French in System > Configuration > General
  6. If prompted, flush the cache. Check Magento Configuration > Cache Management.