Interesting that this has nothing to do with ride sharing (or at least the article doesn't cite that as a reason). I think autonomy and ride sharing will drive used cars nearer to the value of scrap metal within the next 5 years.
As far as automation goes, in the consumer market, I highly doubt it will be anything more than a rich person's luxury for a good long while, since most people can barely afford a $10k vehicle, let alone a $100k one.
You're right that Silicon Valley lives in a cocoon, but more than a few occasions where I thought a SV idea or trend was stupid, unaffordable, and unneeded, it turned out that a few years later the entire world had adopted it. I remember thinking who the hell needs a smartphone and who'd pay for that. Then 6 or 7 years later I saw beggars in a third-world country with smartphones. Beggars.
I'm not ready to say that autonomous cars and ride sharing will be the norm in 5 years, but just because there are poor and rural people in middle America doesn't mean it won't happen.
[1] https://www.census.gov/geo/reference/ua/urban-rural-2010.htm...
I expect full autonomous driving to be much further out. Where it could have an effect though is this. To the degree that new vehicles become much more attractive because of new sensor and software features, that would likely drive used car prices down. These could certainly increase the perceived value of a current model year car vs. one from five years ago.
Consider 2 similar 2015 Priuses, one with 32,000 mi, the other with 92,000 mi. The one with lower mileage will usually net a higher sale price.