If the lights are components, they can be added directly.
If you turned the lights into full actors (you may have your reasons - method of interaction, perhaps), you can add them via a Child Actor Component:
Each of those components will automatically create and maintain the life cycle of the instance of the Child Actor Class. The car can then access the lights via a cast, as above. The CACs can be placed around the car, as needed or even attached to sockets:
The lights can reach out to the car like so:
Edit: but at this point I’d have the lights talk to the car via dispatcher delegates, much cleaner and all can be contained in the car.