Think this is the idea behind the GM Ultium platform (and probably others). They always held out “skateboard” as the goal, although I don’t know if that’s still a thing. Create essentially wheels and a plank that include all the power and drive components, modify to a small set of sizes, and crank them out by the millions. Then each car is a unique body and interior on top of the “skateboard”. As the platform gets to scale, you can drive the cost down, while still making unique cars on top of it - including low end cars

Fire any designer who tells you AI could improve the product.

That would be pretty dumb. It's entirely possible to use AI in the design and engineering phase without AI being in the product that's delivered to the customer. It's also entirely possible for AI to be used in areas like crash mitigation, improving the handling in poor road conditions, or optimizing charging speed to improve battery life. Those uses of AI are largely invisible but offer a tangible improvement to the vehicle without being what anyone would consider luxurious. Choosing to ignore a design option because it sounds like something trendy is a great way to design a product that's a worse value for the money.