He could have literally just told people you need to buy a steam deck and just connect it to the cybertrycks screen, it's really that simple and let's him sell steam decks, and anyone wanting to hack mod or upgrade their car to play video games is free to do that on their own rime. It's a weird unreasonable request lol and it's like dude yeah...
I'm sure you COULD run a stripped down version of any game on any hardware eventually especially if the cyberpunk is parked and not actually using its processing power...
But he could be out here selling steam decks if he just made sure those handheld devices simply fit anywhere in any cup holder or center Console and then connect it to the cybertrucks screen with a software update simple as that. All the truck has to do is accept wireless or hdmi wired input from a steam deck but I'm sure wireless is fine right? Maybe he can sell adapters and holders for steam decks and Controlleys and make special edition cyberpunk cybertruck gaming controller with some legit company and make it actually nice and somethin people want who can't afford the actual truck yet