The Shockwave is a pickup that can be fired to alter the gravity of nearby objects. After firing, this weapon lifts and flips any car it comes near. In the demos, it is less likely to spin the car, but just simply lift it.
Try firing a Shockwave when a car is nearing a corner. Shockwaves will also bounce off walls to follow the track. In the demo, the Shockwave goes a less further distance.