Use the promotional code that appears on the top of this page in the Unity's asset store (https://assetstore.unity.com/packages/templates/systems/2d-parking-simulator-452...). If the code doesn't work please let me know and I'll generate another one just for you.
Don't worry I'm gonna get in touch with Unity's support team. If you just want the assets you can get them here https://looneybits.itch.io/2d-urban-cars and here https://opengameart.org/content/2d-parking-assets