Welcome aboard! Since you are going to try and stuff a diesel into a small car, you may want to read about MAX here:
Our DIY Car: The Quest for 100 MPG
You can read about the trials Jack went through (and is still doing more
) in his efforts to get great fuel economy. He outlines the efforts of adapting a Kuboat diesel to an older Corolla wagon for testing before dropping it into a classic (styled) sportscar. Lots of good stuff there as well as the resources you'll find here.
Good luck to ya'