It's better to have it in the AppData/Roaming/virtuali/GSX folder rather than the scenery folder. In the case of FSDreamteam sceneries, if you were to run the Live Updater, it would just overwrite any customizations you made if you put it in the scenery folder of the FSDreamteam scenery. If there's already one in a given scenery folder, it's what GSX defaults to if you haven't done a customization to the scenery, but if you customize one, having it in AppData/Roaming/virtuali/GSX ensures that it doesn't overwrite what's default with that scenery, and if you use the GSX editor to customize airport parking, it would put it there anyway.