Name 5 that are normal speed and don't involve a pipe organ.
Vehicle shouldn't much matter. Generally outside of home theater type applications I would not tune below 36hz but you should probably consider which sub you are using and model the response. Some subs will perform very well tuned low, others will give an in-car response curve that looks like a two-humped camel which I personally find detestable.
Lastly, consider that most people do not think a completely flat frequency response sounds good and what does sound """good""" is completely subjective. You may want to just plan a way to adjust tuning after your box is built so that you can test what works best for your goals and application.