I got a "final notice" debt collection letter. Can you help me understand what it means?

I had multiple breast tumors removed, and with that, loads of bills. Well I guess I over looked one. I got a 3rd and final debt collection letter.

It says "this will be our last attempt" and that they "will reccomend other remedies." if not paid.
$124 for a community hospital visit.

What does this mean? Can they take my car away (2015 nissan sentra) ? A lawsuit? I live in New York if that helps. I can't pay that bill this month.