Welcome. Our home had a small 2-car carport on the front, with a garage door on it! Within a week there were 2 more walls added. Since the sun seldom just shines straight down along with rain and wind, I see only a small benefit to an open carport for protecting a vehicle. I would go for a minimum of sidewalls and roof, but then enclosing it into a shed probably isn't that much more $$.
What are your plans for it? Good luck.