The driver's seat in your car faces forward for a reason; however, there is a small mirror provided, should you decide you need to briefly re-examine something in your immediate past. It's best to stay in your own lane, but side mirrors are provided should you attempt a lane-change or turn.
Do not be sad if familiar cars turn from the road you are traveling, never to be seen again. Sometimes driver's decide to pull over and rest, and sometimes cars crash. Cars will come and cars will go but the driver of each car is not the car.
It can easily become confusing if you believe you are the car. You are the operator within the car, so no matter what model car you sit, you are the observer of everything happening in and around. The car may cease to exist. It is only the part others see with the human eye.
There are all sorts of cars. There are red ones that go fast and blue ones that have really large tires. There are still others with silver paint and a bed in the back for hauling. There are others still with rust all over and falling apart. No matter the car, it's most important to remember that the car we are looking at is not the person inside.