In the app it says spots can open up any time from 2PM thru 1 hour before the parade start time. On Saturday my wife each tried and she eventually got a spot around 2:45. We tried to see if there was a way to squeeze me in, but the TMs said only if I'm able to get a spot in the app as well. After all the Ride-and-Dine and passholders check in (right around an hour before the parade), they will announce how many spots are left (if any) and will do one final drop. However, on Saturday they told all of us there weren't any extra spots and weren't going to do an additional drop. We saw another couple in the same situation as us, so we offered them my wife's spot and the TM's let them both check in.