Owner Maintence/Diagnostics

Almost nothing...you might be able to do the brakes if and when they ever need replacement (likely never unless you race). You can do wiper fluid....and blades. That's probably about it.

Fortunately there just isn't much routine maintenance either. I personally have done: wiper blades, wiper fluid, tire rotation, and cabin air filter. Brake fluid flush should be possible on my own too when it's time. Fortunately with regen, the fluid is not put through much demand or frequent heavy use. About the only maintenance item I would like to do, but probably won't is the coolant system flush. If somebody figures a way to do it without going into some locked out service mode on the car, then I may do it myself. Otherwise I'll probably be stuck with going to Tesla service.

When it comes to repairs, Tesla has service manuals but restrict them to those in MA state only due to their state laws that require it. A lot of non-Tesla specific stuff (suspension comes to mind) should in theory be no different then any other car. Since there are so few cars now off warranty, it's hard to say how well other shops will eventually be able to repair the cars. If you are concerned about off-warranty repairs, an extended warranty may be in your best interest.