Your questions about carriages actually got me to try making a drivable carriage (before I found out it was already made) and the way I detected followers was to start a quest when the cart is activated.
The quest would have 4 optional reference aliases (since there are only 4 seats in the cart) with the match conditions:
GetFactionRank CurrentFollowerFaction >= 0
IsRidingHorse == 0
The reference aliases had an attached script that told the actors to use SetVehicle and PlayIdle in the OnInit event.
I am doing something similiar for my quest alias... but it does not return the followers. But this gives me some insight... when does the CK evualuate the conditions for the Alias? I was just *assuming* it was when I wanted them, but that's probably not the way it works and why I was not getting the results I expected.
Is there a way to force them just before I send them to my script properties?