How about a coordinated social media 'attack' - in the nicest sense of the word - on Southern's Twitter account before either the next home game or evening fixture? If 'x' hundred/thousand of us all contact them at the same time (e.g. 2pm for an evening game) asking the exact same question, then...
Out of idle curiosity, I looked into this a while back. My understanding is that GTR have been advertising for drivers, and those who have been successful in the recruitment process have been placed into a talent pool awaiting notification of a formal start date. All well and good, you might...