OK - but really, the parking place thing is specifically aimed at people who are there for Prom, but not registered at the hotel at all. The idea is to have the hotel put a small bloc aside for Prom guests who aren't hotel guests; that way, people who are driving in just for Prom and leaving afterward won't have to try for parking or wander around SOMA in their corsets afterward. Not that locals would object, but still...
People actually staying the night are a whole 'nother ball of wax.
In that case, count me out of the needing parking, since I am rooming with Steph and Jess while I am around.