I have now logged about 6,000 miles on long distance buses. They include Greyhound (Canada and U.S.), Elite (Mexico), ADO GL (Mexico), Tica (Central America), and Chinita Risuena (a Guatemalan chicken bus, with a tilde over the "n" in Risuena).
This is my assessment of what seats to avoid, and to select.
Front of the bus:
- Unless there is a curtain between the cockpit and the passenger section, the front seats should be avoided because a) you will be scared shitless when you see how your driver is recklessly driving and b) at night, headlights from oncoming traffic will prevent you from sleeping.
- If there is a frontal impact, you'll be one of the first to go.
- Overnight, the driver WILL turn on mariachi music full blast to keep himself (and you) awake.
- If there is a rear impact, you'll be one of the first to go.
- If there is a bathroom aboard, you will be very uncomfortable with the smell and with people constantly walking by you to use it.
- If there is a side impact, you will get hurt.
- If there is a rollover, you will get hurt.