Things mandated by law in the US: horns, engine hoods, windshield wipers, mirrors, airbags, tire pressure monitors, backup cameras, seat belts, bumpers, anti-lock brakes, automatic emergency braking, electronic stability control, LATCH systems, mufflers/emission control systems, headlights, tail lights, stop lights, and turn signals.

Additionally air intakes may not be more than 4 inches in height, steering wheels must be circular and at least 13 inches in diameter, and tires must not discharge materials towards the rear of the vehicle.

That covers most of it.

Junk I tell yea. I live in Death Valley, CA why are you mandating me to have windshield wipers? Also I’m a very good driver why do I need ABS or automatic emergency breaking? I only text and drive when there is no one on the road.

Some of the junk is from lessons learned the hard way. For example, backup cameras dramatically reduce the chance of you running over your own children in your driveway.

https://en.wiktionary.org/wiki/Chesterton%27s_fence