Tesla's stance on salvage cars is that they don't exist. Your warranty is void (including the unlimited mile/ 8 year powertrain warranty), your service is void, supercharging is disabled, your onboard 3G/ LTE radio is disabled (usually) and perhaps the biggest hassle is the lack of firmware upgrades. The firmware the car is running now is the last version it ever will run. On a non-AP car this might not be horrible but on an AP car where the technology is ever-evolving, you're essentially boned. You wouldn't have received the summoning features or the AP improvements everyone else did yesterday. Taking it even further, Tesla won't fix or service the car even if you pay them. They will not touch it. This means that if you so much as lose a key and need it reprogramed you're totally out of luck. There are many scenarios in which you could have a relatively minor problem completely disable the vehicle because Tesla won't service it.
There is one way to get them to service the car and that's to go through their redemption process. The process is kind of ambiguous and you'll run in circles collecting bits of info from various Tesla employees about what it entails but here's the gist of what I got. Initially there is a $1500 fee. Tesla takes possession of the car and then hands it off to one of their certified body shops who then tear it down and send Tesla a litany of pictures. The body shop I spoke to said that Tesla wants to see very specific areas of the car to make sure they a) haven't been damaged or b) have been damaged but fixed properly. If the car passes this inspection then they will re-enable the onboard radio, re-enable supercharging and allow you to get firmware updates. You can also pay to have the car serviced though your warranty is still void. If the car doesn't pass you're on your own. You've paid $1500 for the pleasure of being told that your car isn't fixed properly.
I bought a fixed, running, driving 2013 S85 for $20,000. It needed a frunk liner, a few small sensors and plastic trim pieces under the hood but on the outside it looked great and on the inside it was like new. Despite that, I couldn't bring myself to own it without being in a constant state of panic. So I sold it to someone else and spent $30,000+ more for the same car with 17,000 more miles on it and a panoramic roof. To me the piece of mind in having the warranty was worth the difference in price, plus I made good money on the salvage car which helped pay for the one I bought.