To have one person drive wrecklessly while the other passengers jump from the back seat to the front.
Whoever sustains the most external injuries wins.
Some car gymnastics may have a points system though it is not required
Ex: Bruise - 1pt
Injure Driver/other gymnast - 5pts
Consussion - 10pts
Blood/Bleeding - 15pts
Permanent Damage - 20pts
*Wreckless driver speeds down street then turns violently*
Gymnast one will jump from backseat to the farthest point in the front interior of car.
Gymnast one totals 4 bruises and a bloody nose = 19pts
Gymnast two kicks driver and collides into windsheild = 15pts
Car Gymnastics winner would be Gymnast one.