Rocket League Collector's Edition DLC

You will need to already own Rocket League to be able to use this. This will give you the following:

INSTANT ACCESS TO 4 NEW CARS:

Esper, Masamune, Aftershock and Marauder

As you play through the game, you will unlock everything else, including all of the DLC pack items from Chaos Run, Supersonic Fury, and Revenge of the Battle Cars.

2nd image shows the cars that will be unlocked.