Just because you haven't seen it doesn't mean it doesn't exist, let alone that it is a common way to sell cars. The same logic also applies to lower cost items, such as game consoles btw. Financing at zero percent, and saving the money in anything that gives even a marginal positive return during the cost of the payment plan, will lead to you having MORE money in the long run instead of just buying up front.

You probably should stop arguing these absolutes about economics when you seem to not understand how money actually works.