Why would one need to go for the other to be saved? There is ample parking everywhere and neither building has a large enough footprint for a parking structure. Actually, the best chance either one has to be saved, is if the other is renovated.
Ample parking? In Detroit? I think you'll find that a majority of large tenants looking to come into the city are citing the lack of parking as the number reason for not making a move downtown. Take a look at the cover of Crain's this week, David Friedman's entire strategy for Dan Gilbert was centered around parking.