Offer an option to store some Spotify or Slacker content/music within the car to the USB to maintain music when going through areas of limited or no cell coverage.
In areas with low or no cell data coverage Spotify isn’t always working or is slow to buffer. On mobile devices you can set content to be available offline. Spotify will play this content from local storage instead of streaming it. It is also possible to store offline content in higher quality.
This would benefit the owner with quality and low latency, and Tesla with lower data transfer for the already synced content.
The sync option might require a USB flash drive to be attached for storage.