If you're tired of the subtle messing with her (which, and I know I don't speak for anyone else, I wouldn't be) another option is to just part in her saved spot, running right over the cone, leaving it crumpled in a heap under the transaxle. Just give a huge flaming F*** You to the cone, the idea of the cone, the space saved by the cone, and the person with the gall and gumption to bring a cone into this environment.
I have to say, though, I don't imagine that someone with the temerity to bring a cone into a parking garage in order to secure a spot is going to go gently into that good night.