Not to sidetrack this thread too much, but what are you seeing for 2014 P85 asking prices that leads you to believe the values are so weak for non-auto-pilot cars? I sold my non-AP 2013 S85 about 6 months ago for 64% of original sticker price (this was month 35 for the car while the RVG trade-ins are months 36-39, so I think it's comparable). The RVG did not yet exist when I bought my car, but if it had, the guaranteed buyback price would have been 47.5% of sticker price (that's 50% of the base price plus 43% of all options.) That's about $15,000 lower than what I actually sold it for, so my experience is resale values are holding up substantially better than the RVG and also substantially better than other similar situated cars like full-size sedan Merc/BMW/Audi/Porsche.
I would be very surprised if used prices have moved that much lower in the last 6 months such they were at or below the RVG prices. More likely IMO that many folks are just not appreciating just how much depreciation all higher-end cars see in the first three years. The resale guarantee is a good program for folks very nervous about whether Tesla's in business in 3 years. But it's really just that, catastrophe insurance (and expensive insurance at that, given the otherwise much lower loan rates available). It's not gonna save you from the depreciation that all high-end sedans see.