One thing that i think would have worked is if they re-arrange the large landscaped area that transitions condor flats to grizzly.
They should consider re-arranging the main pathway and then using the pathway area and landscaped area and turn it into a small town. something with various entry point (think new orleans square). Large trees and brush would create a lush landscaped area between the hotel and the small town.
Once that is done, then i would go ahead and relocate the fly n buy shop to that area. People would basically have to walk though the area and would give the shop more foot traffic. Then the area occupied by the shop as well as the area next to it being used for the Cars meet and greet would be gutted out and repurposed for mullholland madness. Lots of new landscaping and a proper facade themed to the area would give Condor flats another attraction that the family could enjoy.
If Mullholland madness could not be concealed properly in that area then another option would be to add a small family/child friendly coaster similar to the barnstormer in WDW. Basically the idea would be to give adults an option of something to do with their young children, themed to match Soarin, while the rest of the family rides Soarin.