Just got the trophy! I am with Rocket League Game of the Year edition and 24 cars in the garage, and Car Collector still dont pop up, but here is what I did: 1. Backed-up my local saved data to Cloud with Ps Plus ( or you can use USB ) 2. Erase the local saved data from my PS4. 3. Start Rocket League game OFFLINE!!! 4. Trophy popped after FIRST WON GAME WITH OCTANE CAR. 5. Finally restore previous save data to get all your save things again. Now I just need some trade for Drops in the Bucket and Stocked trophies. Help will be appreciated P.S. All users with paid version of Rocket League dont have to buy 500 credits to start trading items.