Chris Ziegler, writing for The Verge:

Meanwhile, let's take a look at Tesla's track record. Every Model S and X on the road today runs the same software version, delivered over the air. It started installing the necessary hardware to enable Autopilot a solid year before the feature was actually enabled. Model S vehicles built before that are out of luck, yes, but you have to start somewhere.

[…]

But a car from virtually any other automaker is a time capsule. Ford has been pretty good about upgrading Sync on production cars, but that's strictly infotainment — you won't likely get a new instrument cluster UI in your 2016 Ford Fusion, unless there's some sort of weird recall. You won't get a new regenerative braking algorithm pushed to your Chevy Volt as it sits in your garage overnight. Generally speaking, your car will not be made better over time.

I love my Model S, and I can attest to the ongoing improvements. I've received several OTA software updates that improve things like rain-sensing wiper algorithms, maps and routing logic, and even a pretty major UI refresh shortly after I bought the car. It is very much like an iPhone or Android phone that gains new features over time—for free. My car was purchased used, and was built before Autopilot was a thing, but I'm not complaining. In the 4+ months that I've owned it, I've received several improvements, and definitely feel as though I own a better car now than when I bought it.