re: How would you advise a genuinely broke person regarding buying a car?

I assume he lives in the semi-rural Deep South, since in most other parts of the country he could rely on public transit. He needs a short term solution while he works on the longer one: he needs a carpool, stat. Ask around at work, or in the building, or at nearby businesses. He may be able to walk/bike to a pickup spot, where someone going in his direction will take him the rest of the way to work. Think of it as "assisted hitchhiking". Depending on his locale, he might find a carpool through craigslist or social networking. A post on FB describing his route to work w/a request for friends/family to share might generate a ride....

Which brings us to the longer term solution. He needs to cancel all non essential repeating bills: landline, cable, whatever else he's paying every month that's not utilities/rent/heath insurance/food. Then he needs to find supplemental work...he's not going to make this happen on his primary income, so he needs a side hustle. Bartender, grass cutting and weed pulling, tutoring, swimming lessons, odd jobs/carpentry, house or office cleaning, pet sitting, etc. There are a slew of things you can pick up to make a little side cash.....plus, everyone in the household needs to be contributing. Significant other, kids old enough to work: no one should be sitting on the couch, everyone should be contributing to the support of the household during this push to re-establish reliable transportation.

Many of us have been in this situation, and we often pulled through with a combination of busting azz and a little help from friends. We also learned to spend carefully, to trade wants for needs, and to help out others who might be in a similar spot. You sound like you might be in a position to help him a little bit--