There might also be other Autobots such as Bumblebee. Bumblebee could be Harry's friend, always there to help him out in tight situations. Maybe there's a human - Autobot liaison character who helps Harry understand the Autobots better. And let's not forget, there could be some antagonists from either the wizarding world or the Decepticons' side who play important roles in driving the story forward.
Well, one possible interesting plotline could be Harry teaming up with the Autobots to fight a common enemy. Maybe there's a powerful Decepticon that threatens both the wizarding world and the Autobots' home planet, and Harry's magic combined with the Autobots' technology is the key to victory.
One possible storyline could be that after years of war, an Autobot and a Decepticon realize the futility of their fight. They secretly meet and start to communicate. They find that they both have similar desires for their home planet, Cybertron. So they decide to work together to bring about peace, facing opposition from both their factions.
One interesting Naruto Autobot fanfiction could be about Naruto somehow getting transported to the Transformers' universe and teaming up with the Autobots. He might use his ninja skills in combination with the Autobots' advanced technology to fight common enemies.
One possible theme could be redemption. The autobot might help the suicidal reader find a reason to live, like showing them the value of life in a new way.
Kakashi could be another important character. His intelligence and wide range of ninja techniques can bring a different aspect to the story. And for the Autobots, Ratchet is often used. His role as a medic can be interesting when combined with the ninja's healing techniques in Naruto.
Starscream could also be a main villain in this fanfic. He is always looking for a chance to gain power and prove himself. He might see the battle of Autobot City as an opportunity to take over the Decepticons or get some valuable Autobot technology for his own gain.
One common theme is self - discovery. The male OC often has to figure out his place within the Autobot group and what makes him unique. For example, he might discover a new ability that sets him apart.
The exploration of new relationships. In 'Transformers Prime Autobot OC fanfiction', we can see how the OC interacts with the existing Autobot characters. It could be a friendship with Bumblebee that's based on their shared love for speed, or a mentorship under Optimus Prime. These new relationships expand the narrative possibilities. Also, the fanfiction often delves into how the OC adapts to the Autobot's code and values, which can be really fascinating to read about. It's like seeing a new piece of the Transformers Prime puzzle being added.
I'm not sure of a specific one off the top of my head. But you can try searching on fanfiction websites like Archive of Our Own. There might be some stories that match this concept.