If they show a car driving I believe it's capable of self-propulsion and not just rolling downhill.

A marketing trick that has, in fact, been tried: https://arstechnica.com/cars/2020/09/nikola-admits-prototype...

Used to be "marketing tricks" were prosecuted as fraud.

still is. Nikola's CEO, Trevor Milton, was convicted of fraud and is awaiting sentencing.

Oh. Good to hear. Thank you.

If I recall correctly, that led to literal criminal fraud charges.

And iirc Tesla is also being investigated for fraudulent claims for faking the safety of their self driving cars.

Hmm, might I interest you in a video of an electric semi-truck?

When a company invents tech that can do this, how would their ad be different?

No, but most people tend to make a mental note of which companies tend to deliver and which ones work hard to mislead them.

You do understand the concept of reputation, right?

this was plausible