Your score depends on how many enemy cars you destroy, how many crystals you collect and how long you manage to hold onto them. The longer you hold crystals in battle, the higher your score will be. Each player can hold up to 7 crystals.
Whether your team wins or loses depends on the amount of crystals all members manage to collect by the end of the battle. You can end the battle ahead of schedule if you collect 15 crystals and hold them for 20 seconds.