Psyonix has announced that Rocket League will be patched on August 29th to bring the "Progression Update" online. In the entirely new system, the level cap will be removed and it "flattens the amount of XP needed for leveling up". In addition, players will be able to create, manage or join Clubs of up to 20-members each. Lastly a number of new achievements and trophies will be added alongside various quality of life improvements.
The new progression system is being moved from "offline" to "online only" so that "no player can 'game the system' to earn levels, titles and other unlocks".
As players gain XP and progress through levels, they can earn random items of Uncommon rarity or better. This is done to make earning free items more "consistent and predictable". At various benchmark levels, all of a specific type of item will unlock. "For example: You will unlock every common Topper after 15 matches" and so forth.
When the new system goes live, players who have previously earned XP will have it converted to the new system, though the math behind how that happens has yet to be revealed.
Want to know more? Head to the Rocket League site.