https://www.gamespot.com/articles/alongside-wrestlemania-rocket-league-is-getting-ww/1100-6458005/

When developer Psyonix announced a partnership with WWE a few months ago, it mentioned that wrestling-themed items would be coming to Rocket League. Now, we know what those items are, when they'll be available, and how you can get ahold of them.

There'll be 11 WWE items in total coming to the game this week, although you won't be able to get all of them right away. On Sunday, April 8, during Wrestlemania 34, Psyonix will release a special code that'll unlock two random items from the group of 5 banners, 5 flags, and a set of wheels.