Dean was adopted by David and Denise Clarkson as an infant and lived in the same suburban town and neighborhood his whole life. He started helping his dad fix cars at five and learned quickly until he was taking care of the family cars himself at eight. He has an uncanny ability with mechanics. Other than that he’s pretty ordinary if rather above average in intelligence He did fail shop three times in high school for his inability to actually write down or explain why what he did made things more efficient.
Family-wise, he’s had a pretty ordinary life, both parents worked, came home at five and they all worked together or traded shifts for home cooked meals. The house was always open to whatever friends he wanted over and his mom tended to explain the parts of social behavior that he didn’t get himself. He’s had a few girlfriends, the most recent, Karla lasted over six months. Usually they last about two. He tends to acquire them through fixing their cars.
He was offered a place at a private NYC high school, and had decided to take it, which meant he was moving away from home. Also, he recently came into an inheritance from his biological mother’s family. Soon after that, his parents died in a freak car accident for which he blames himself. He is now on his way to NYC, and has rented a larger apartment than he’d have been able to otherwise, as well as a garage to store his motorcycle that he’s built from the ground up, and the wrecked car he is still investigating to find the cause of the accident.
Since then he has discovered he's a lot less ordinary than he thought, being the son of Tony Stark, and Kathy Dare. He's moved to New York, moved in with Tony as they try to figure out their relationship as a grown man and biological son, and become the hero War Machine. He still retains his occasional naivete and his view that most people are truly good people.
Although he's learning to be a hero, he still hasn't given up racing in the not exactly legal arenas. He lives to test his cars and bikes against the best he can find.