Quoted from DavidPinballWizz:
A second bicycle girl will not give you a multikill, unless you did not earn it the first time.
If you play for example terminus (6th mode) and then play the modes all over again, I think you can earn them back for the modes.
Just heard the greatest quote today (factory software):
"they're gonna feel pretty stupid when they find out, ..."
thanks- I feel I need to try to pay better attention to which Multi Kills I'm achieving then- so I know what's left.