Make a couple of USB power ports available to the back seat. This is useful for charging and running phones and tablets as entertainment for the back seat passengers on long trips.
A cheap under $20 alternative is getting a USB power plug. Models have one or two USB ports and plug into the 12V accessory port. These usually provide up to one amp per port, for fast charging rates.
As of 2019, rear USB charging ports are provided in all Tesla vehicles.