As I mentioned in another comment I'd be surprised if Tesla didn't tell people when they were handed the keys that they were getting extras to "try out".

That said you do have a good point on their return policy.

Test drives are a different beast altogether though. At least when I got my Tesla 4 years ago it wasn't common to test drive the same exact configuration you were ordering anyway since everything is custom built.

I guess for both of these items if they were to come up I'd hope Tesla would be generous, but I still see nothing wrong with them removing features people didn't pay for.