Build the cupholders first, delivery them to the client, and re-reevaluate. Maybe the client was only looking at cars because that's where they've seen cupholders before.

To be fair, the Civic does look a little funny.

But yes, there should be more emphasis on what drives business value (hence on picking a stack that allows providing that value as efficiently as possible), and with the minefield that's modern web development, starting from scratch doesn't seem sensible. The post doesn't go too deep into what they're building though, so maybe I'm missing something.

The article said they're building cup holders and didn't want them to come with a car.