Modern car windows are glass laminated in a transparent plastic, since glass is too fragile on its own. The polymer sticks to the material, even in a crash. That prevents the glass breaking into large pieces and instead forms the spider-web like pattern that we see. It is important for glass to be transparent because the driver needs to see where she/he is going. It is also important for the glass to be waterproof so the interior of the car stays dry. Glass in cars has tightly-packed molecules that allow it to be waterproof. Yet if it is distorted then the molecules cannot be packed together as tightly so, as a result, the glass is weaker.
Car tyres are different materials mixed together that give better properties. The rubber it is initially made of undergoes a lot of processes that meld it with other synthetic substances and chemical curatives that make it much more durable than regular rubber. That property is important for the tyres because they are made to last for some time. It also needs to be flexible and strong for it not to be broken by a random rock lying on the road. There are many crosslinks formed by adding all the additives to the rubber.
The car frame is usually made of steel, even though aluminium is less dense and can be strengthened in the manufacturing stage. But that process usually makes it much more expensive. The car frame has to be strong under pressure (to support weight), waterproof and non-reactive to the elements. Steel forms a layer over itself to prevent it from rusting, is naturally strong and atoms have strong bonds like most solids which does not allow substances through. Steel is strong because its single molecules can be easily packed together very tightly.
Car seats are usually made of tightly-woven nylon coverings and shaped foam which is supported by a metal frame. Nylon is used because it is cheap and wear-resistant while the foam is there for the driver’s or passenger’s...