Hi Josie, :welcome:!
Great first post. Love it when new members add somthing new with their first post.
I followed this, and was impressed with how you solved the problems of locating the bulb and battery. Particularly impressive was the use of the screen door handle - I bet that was the inspiration for the whole project.
The end result is rather useful, and good for the car. Well done! My only suggestion would be to add the refinement somehow to put a "foot" on it, so the handle is always uppermost when you put it down. I know you can tailstand it when you are not using it, but having it horizontal but still easy to grab will make it easier to use.
One question: - you intend it for the boat - does it float?