Mmmmmmmm. Baaabiessss.... aararrrrrrrggghhhhh (*drooling*)!
And that is precisely the difference between a Wharton grad and a non-Wharton grad.
Part of the reason why Wharton graduates are so sought after by recruiters is that we're trained to see all financial transactions as potential investments. In the case of cars, you see it by realizing that the 20k worth of depreciation could earn substantial returns if invested in a different manner.
In other words, you're right in a technical sense -- but not in a sense that's helpful if you want to retire by the age of 40.
a car isn't an investment;
If you spend money on it, it's an investment.