The leather seats.

When you buy a car, the sales guy will try to sell you a lot of add-ons: the leather seats, the wooden interior and whatnot.

The thing is, if you don't buy any of them, you still get a car.

What makes a car, a car? What can you remove and it stays a car?

And what can't you do without?

We can agree that without the engine (or the motor), the tyres, or the chassis, you no longer have a car.

What about your work? What are you making?

Are you focussed on the leather seats or the chassis?