Some Utilities that may be of use to you.
This will prevent your files from being deleted when you deregister your Kindle.
Steps:
Yep. You found out about audiobook and music players for the Kindle, but there's no Bluetooth option. Here's why and a solution
It happens because Amazon is greedy and region-locks the software setting to only Audible regions, deregistered devices also are regionless and don't have store so thus no Audible and no bluetooth. But the hardware's still there and can be activated using these scriptlet pairs.