A brief description of the current functions that have been the same almost from the start of motoring will show that:- The wheels are crucial. Four pneumatic tires provide the bed on which the vehicle can move in the direction required. The tread on the tires is critical because on a wet road the water needs to have channels to escape. Water does not compress so if there is no escape route the whole car could suddenly be aqua planning without brakes or steering. Improvements in the tires have been ongoing and many millions of dollars are spent annually by the tire companies and tested on race tracks. Wheels which originally had spokes developed through steel and now many use metal alloys to mould the wheel. The advantages of alloys are the strength vs the weight. The heavier a wheel is the greater the rolling resistance which is why some hi performance cars use big alloy wheels with low profile tires which cuts down on the rolling resistance and thus improves the performance.
Steering is likewise critical. Many of the earliest cars used a tiller arm to steer but all cars now have a steering wheel backed up by a steering box in which direction is determined by steering arms guided by a Rack and pinion arrangement which is very positive. Many modern cars have hydraulically assisted steering which eases the effort of turning at low speeds. These have to be damped down the car speeds up otherwise a slight twitch could get the car into a spin. Another critical part are the brakes. No car should ever be on the road if they are unable to stop in a short distance. Originally brakes were actually blocks on the wheels, rather like those on bicycles, then shoe brakes in drums were introduced. Now most use disk brakes.
Safety belts were not introduced until the 60's but now it is illegal for anyone to travel in a moving vehicle unless they are strapped in. This has cut down the mortality rate of passengers in car accidents considerably. Obviously these are basic functions that have not basically changed over time except in development and upgrading. As far as upgrading goes Infiniti crossover cars have taken all these functions as read and built them in to a fun new package. crossover cars take many of the features and functions of luxury cars and build them into an automobile that is in fact almost a sports utility vehicle (SUV). The wheels are alloys the brakes are disk brakes and the tires have a decent size but a broad tread to give a decent footprint on the road and not allow undue sliding. The steering is power assisted thus the cars are easy to steer at low speeds but the damping effect means a more positive action must be used at speed. Cross over cars generally are luxury cars with an attitude and that is what an Infiniti crossover achieves. A luxury car on steroids.
