Openable car doors are already planned for V3. But how you open and close the vehicle door and how you enter and exit the vehicle hasn’t really been heard or discussed. So I have a suggestion on how this feature should work in V3.
Entering a vehicle:
You will approach the vehicle within 5 studs of a door handle and click the door handle. The door of that handle will open. You will then click on the seat to enter the vehicle. That door will automatically close once you enter the vehicle. All doors will automatically close as soon as your vehicle reaches or exceeds 10SPS.
Exiting a vehicle:
In order to exit your vehicle, your vehicle must be traveling less than 10SPS. You will hit space once to open the door. You will hit space again to exit the vehicle. After exiting the vehicle, you click on the door handle of that door you exit from to close he door.
With this feature, vehicle doors, windows, windshield, and roof should be collidable.