This is a paid asset, but now you can download Advanced Car Enter and Exit Free.
Detail this asset from Unity Store: Original Link
Advanced Car Enter and Exit v1.0
Add Car Enter and Exit mechanics to your game with ease.
– Easy to setup (Drag and Drop Inspector)
– Most important values accessible from the Editor
– Demo Scene and Prefab included
-> No programming required
Adding an Enter and Exit mechanism to your game was never that easy. Simply Drag the prefab into your existing scene and you’re ready to go.
Do you want to be more specific? You can..
– Choose exactly which Car scripts you want to deactivate
– Enable support for specific Car assets (Unity Standard Assets included)
– Add additional things to do when Entering or Exiting the car with the Inspector! No coding required. (Switch HUDs, Change Values, etc.)
This asset is designed to be lightweight so that it does not bloat your existing project. If you want to start from scratch however, you can also import the included modified Unity Standard Assets to kickstart your Project.