The guys at Tesla Model 3 Owner's Club put together this excellent video installing a BlackVue dashcam. Though it's not an easy task to follow their method exactly, it's really a clean look when done. Of course, Tesla may make dashcams irrelevant by allowing owners to access and use all the cameras already installed in car, but who knows how long that will take, or even whether or not for sure (despite Elon's assurances) it will happen.