They might be related in terms of the theme of happiness and luck, or maybe the car is a central element in a cartoon world filled with positive vibes.
A cartoon boy can be happy when he achieves a goal he set for himself, like winning a game or getting a good grade. Also, having a loving family that supports him can bring a lot of happiness.
She could be happy because she accomplished a difficult task or just because the home environment is cozy and peaceful. Also, it might be that she had a delicious meal.
There were many anime works that had happy endings, such as Your Name, The Gate of the Fate Stone, Attack of the Giant, Spirited Away, Inuyasha, and so on. These anime works all told beautiful stories that made people feel happy and happy. Their endings were all positive, bringing hope and joy to the people.
In some fanfictions, Laki could be part of a team - up with other less - featured characters in Fairy Tail. They could form a sort of underdog group that takes on missions that the main characters overlook. This would give Laki and her group a chance to shine and show that there's more to the Fairy Tail guild than just the main heroes we usually see.
A happy face cartoon girl typically has rosy cheeks, a twinkle in her eyes, and a friendly demeanor. She might be shown playing or interacting with others in a positive way.