It was (and remains) an investment in the sense that it allowed you to live in a nicer place farther from work, or to commute to a job you otherwise couldn't take.

But was it ever an investment as an appreciating asset per se? I'm not aware of such a situation but I'd be interested to learn otherwise.

Yes, buying a car was an investment as in you can buy it and then later sell it used for a higher price than you bought it.