Rocket League is going free-to-play on Wednesday, and Psyonix and Epic Games are marking the occasion with a crossover with the publisher’s other big free-to-play title, Fortnite. Llama-Rama is Rocket League’s first in-game event after the switch, and it’ll drop Fortnite’s famous Battle Bus into the car soccer arena.

The event starts on Saturday at 6PM ET and runs until October 12th. You’ll need to complete challenges to unlock llama-themed event items, including a topper, wheels, decal and antenna. Once you’ve earned them all, you’ll snag the Battle Bus as well. Just remember to thank the driver whenever you score a goal with it.

Over the last couple of months, Psyonix has been explaining how various aspects of the free-to-play transition will work, including cross-platform progression. There’ll be an update for existing players tomorrow (September 16th) that will allow them to link the game to an Epic Games account. Once you’ve done so, you can access the Rocket League items you’ve unlocked across all platforms. Those who already own the game will also receive Legacy items tomorrow, and the update includes other additions and quality-of-life changes.

When Rocket League goes free-to-play next week, it’ll debut on the Epic Games Store. If you claim the game there by October 23rd, you’ll get a $10 coupon you can put towards any game or add-on in the store, as long as it costs at least $14.99. If you download Rocket League from the Epic Store, you’ll also get a couple of bonus cosmetic items when you fire it up for the first time.

It appears there’s a Fortnite-related in-game event in the works too. Psyonix said it’ll soon reveal more details about a Llama-Rama event, which’ll start soon after the free-to-play move.

After every match, you’ll have the chance to snag a blueprint, which explains upfront what item you’ll obtain if you buy it. You can pay for a blueprint (and item) immediately, or you can hang onto it in your inventory to purchase later. As with crates, painted, certified and special edition items will be available through blueprints. Psyonix also has a new item shop on its roadmap. It’ll feature older items that appeared in crates along with new ones.

Both blueprints and the item shop will arrive in December, along with credits, which are replacing keys as the game’s premium currency. You’ll also be able to use credits to buy Rocket Pass Premium too, but they won’t be valid for the esports shop — only esports tokens will be valid there. Psyonix will automatically convert keys into credits and remaining crates into blueprints once the overhauled system goes live. Until then, one final vindicator crate will be available from Thursday, which includes a battle-car and a goal explosion.

Meanwhile, changes are afoot for Rocket League trade-ins. When the new cosmetics system is up and running, you won’t be able to trade in paid-for items from blueprints, the item shop or older ones you got from crates. You’ll still be able to trade in items from free post-game drops.

Psyonix reckons blueprints will offer more transparency about the digital goods you’re buying. A major criticism of loot boxes is that you don’t really know what goodies they contain. Some jurisdictions and regulators believe they’re a form of gambling.