Elon Musk has come up with a clever way to drive Tesla sales: Tell potential buyers, if they get Tesla cars, they're investing in their own Uber fleet.

The Tesla CEO said Tesla cars could one day make money for their owners as self-driving, for-hire cars. They'd be able to autonomously transport people when their owners are not using them, and the best part is, Tesla cars already have the hardware they need to do so. There’s a small camera above the rear view mirror so that owners can watch what happens inside their car when they're not around.

Its “there for when we start competing with Uber/Lyft and people allow their car to earn money for them as part of the Tesla shared autonomy fleet. In case someone messes up your car, you can check the video,” Musk tweeted on 5 April. ”Just a matter of finishing the software and going through regulatory approval,” Musk added, when someone said this concept was hard for them to imagine.

Another user told Musk that figuring out the software needed for a shared autonomy fleet would "fundamentally change car ownership as we know it" - to which Musk said, "Yes, instead of someone needing to drive their car personally, they can manage a fleet of self-driving cars."

Now, this isn't the first time Tesla has teased Uber-like ambitions. During Tesla’s conference call in October, Musk promised Tesla will operate its own "ride-hailing services and compete directly with Uber and Lyft, obviously" (via CNBC)

To be clear, Tesla offers some self-driving features via its Autopilot function, though they all need a driver to actively supervise. Tesla cars can autonomously match speed to traffic conditions, keep within and change lines, transition to and exit freeways, self-park, and be summoned. But all Tesla vehicles have hardware with “full self-driving capabilities,” according to Tesla's website.

This hardware can be fully activated with a software update, and Tesla has said it will when it has “billions of miles of experience”.