Anyone would not want to ram their car against another since that will not only damage their car, but might also hurt them in the process. Those who does that are crazy and dangerous that needed to be put in jail. Besides, what can you gain from it?
The idea of the game is to ram your car against another vehicle on the road. Destroying cars earns you money, which you can use to buy some upgrades for your car. To get some boost, try to find some utility trucks and ram it. The game gets harder and harder as you make some progress.