USA Bus Lines

What is the best bus line in Mexico to travel from Monterrey to Piedras negras Coahila?

Long story short, my little sister went on vacation to Costa Rica, and was not able to fly due to her passport. Anyhow, best was was to fly in to Mexico city and she will fly from there to Monterrey and that is as far as the airlines will go. We need to get her to Piedras Negras Coahila but I don't know any buslines down there. Any suggestions?? Thanks in advanced.

Public Comments

1. Here is a Website with all the necessary bus information http://www.larpman.com/transportpages/buspages/buswi.html
2. Piedras Negras is about 600 km from Monterrey, you can go in ADO or Coahuilenses, both are fine, anyway Coahuilenses also travel to USA, Dallas and San Antonio... Good travel!