Great info here. Confirming this works. The automated system doesn’t do a good job of voice recognition of the letters in the car number but you can enter the letters using the phone dial numbers (enter TTGX as 8849) then when prompted enter the remaining numbers.I've been tracking mine (Norfolk Southern) through their phone number.
1-800-635-5768
Option 2, Option 2 -> input your personal TTGXXXXX #