Japanese already tested it, with googly eyes. It seems to work. Modern cars are expensive, some extra plastic and servos is not going to break the bank.

https://dl.acm.org/doi/10.1145/3543174.3546841

https://www.dailymail.co.uk/sciencetech/article-11250965/Jap...

https://videos.dailymail.co.uk/video/mol/2022/09/26/56244997...

British used a LED matrix. More "output" options (frowns and smiles, text), similar results.

https://www.nottingham.ac.uk/news/first-ever-uk-ghost-driver...

https://www.theengineer.co.uk/content/news/pedestrian-study-...