> I'm sure there are always some models available under 20K

Since you are sure, can you name a few?

You can't because none exist. There are no new cars in the USA for less than 20K.

The alternatives offered here are nonsensical. Where in the US does one buy this youtube solar car or KEI cars? Nowhere, that is where. They are not sold in the USA.

Golf carts are legal on hardly any roads so that is another non-starter unless you live in a neigborhood where they are allowed and never plan to go anywhere outside of it.

Cycling is great, that is the only practical suggestion on the list. But of course a bike is not a car so if someone actually needs a car, a bike is not a car.

For anyone poor who needs cheap transportation, old beater cars are the best.

Don't have to be poor either, for anyone who doesn't want to throw good money away at depreciation, old cars are the best deal. As an engineer in Silicon Valley I could technically afford many kinds of expensive cars but I've yet to ever spend more than 20K on any car or truck. Buy used, keep forever, that's the best.