I just had a thought about how we could distinguish between demo players.
When they join, send a big IS_BTN giving them a unique passcode. and then, a box to enter their email address.
Every time that a demo player has to join the race, then they have to put their email and passcode in. Maybe not have the passcode as a IS_BTN, but have it sent in the email verification.
I am thinking about doing this for LTC. Dunno though!