This year's Haunted Hallows event in Rocket League will feature a bunch of Halloween-themed cosmetics for your battle-cars, adding trails of autumn leaves and spider paintjobs and the like. All of them are earnable with 'Candy Corn' currency, which you get for playing matches during the spookytimes.
But as well as the generic Halloween stuff, this year there's also a Stranger Things tie-in. The Farmstead Arena will become part of the Upside-Down, complete with a red sky and the Mind Flayer looming in the background. Some of the other new cosmetics include a Demogorgon banner and title, Scoops Ahoy avatar border, Hawaiian Hopper decal, Camp Know Where hat, and a rocket boost that's all red swoosh.
A couple of those will only make sense if you've seen the third season of the show, which you should because it's quite good. The Haunted Hallows event will go live on October 14 and continue until November 11.