In a post-apocalyptic world, everyone needs to be tough as no one will take care of you. If you are not tough enough then others will simply take advantage of you. You might not think it is necessary, but that is the hard truth in life. They don't care on what happens to you as they just care for themselves.
Drive your car as fast as you can till you reach the finish line. Blow up some cars along the way. Stay away from those bombs on the road and you also need to remember that you must not get too close to other vehicles as that will damage your car. You can pick up some ammo on the road.