I propose another possible way to explain how the "Phase" powerup would work. I like the cross dimensional idea, but what if the Phase worked by increasing the space between the atoms in your vehicle, or weakening the atomic bonds? This would allow the atoms to glide past one another like water as the car went through another vehicle. Queadah's idea would work nicely, too.
OK, tell it to me straight... in Rollcage Stage II for the PS1... was Winter Wonderland II even possible to Gold Medal...?
Retreating is Running Away. Falling Back, however, is simply Advancing in a Different Direction.