I'll add this to our list of suggestions for future release.
We'll see if this is something we can implement.
Right now, the plan is to have Fuelly and our servers be the location for storing the data.
Ex; GasCubby (iOS) and aCar (Android) users would sync their data to Fuelly, and it's stored/visible online here.
But we'll see if being able to backup that data further to a cloud service is possible.