Answer:
I like to twirl my body but keep my head up high. After I go in everything becomes tight
When you are inside me you will be encouraged to slam other cars.
I twist and turn and leaves a loop
The person who makes me doesn't need me. The person who buys me doesn't use me. The person who uses me doesn't know it. What am I?
A dragon's tooth in a mortal's hand, I kill, I maim, I divide the land.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.