Um. A lot depends upon what State you’re in. In New Jersey and Massachusetts, two States of which I’ve lived in, auto insurance is “no-fault”. That means, in general, that your insurance company pays you minus the deductible, and then runs the other insurance company ragged on your behalf. In a couple of cases, they’ve even recovered the deductible for me from the other guys. In no-fault states, the insurance commission for the state has teeth and will scare the gee-whillikers out of a company that doesn’t pay up.
In other states it’s you chasing after the perp’s insurance company. This happened to me in Indiana one year and you would not believe the hoops those people put me through. It’s not unusual to have to hire your own personal lawyer to go after the other guy’s insurance company. And now you know why lawyers often lobby, hard, against laws that makes a state’s insurance no-fault.
Two things. If you have the video of the perp hitting you, preserve that sucker. You’ll need it.
It’s also a very good idea to get the police to show up and officially write up an accident report. Without that or the video, it’ll be your word against the other driver’s, and that’s assuming the rental company can find (or wants to find) the perp.
In any case, contact your insurance company asap. It’s often written into the policy that you have to do that. In fact, right this minute, get out your magnifying glasses and read the mouse print. Nobody else is going to do it for you. Get started, and call the insurance company.
One exception about calling your insurance company: if the damage is fairly light, the deductible is pretty close to how much it’s going to take to get it fixed, and your particular insurance company is infamous for raising rates for having an accident, even if it’s not your fault. In that case it might just be smarter to fix it yourself and swallow the costs. But that’s a pretty narrow window, given that Teslas are kind of famous for being expensive to repair.
Get moving.