This has been bugging me as well. I've not been able to solve it 100% but I created a quick and dirty app to help a bit. I can always find the device directory, but I've not yet found a way to track down the bundle / sandbox directories reliably. Source: https://github.com/somegeekintn/SimDirs
Edit: Went ahead and started scanning mobile_installation.log to find additional locations. Seems to find everything now.