Call your local health department, or google the food safety laws in Michigan. You should be able to find your state's health code online, but it may be a bit confusing to try and sift through all of the regulations. Each health inspector and plan checker have different things they choose to focus on, so it can really vary.
Generally speaking, you can't sell food that was prepared in a residential kitchen. You would need to build a second kitchen to commercial standards, or otherwise rent space in a commercial kitchen where you would prepare the food. In terms of holding temperatures for food, your car would not be adequate. You'd need to rent a food truck with NSF-certified equipment/containers to hold the food at the proper temperatures.
That being said, there are a gazillion people all over California who sell all kinds of food to local businesses. For instance, every neighborhood has a guy who sells tamales door-to-door. I'm positive none of these guys have a health permit or a commercial kitchen - probably just a wife who is a great cook. (I love tamales and always buy a few dozen when our neighborhood guy comes around!) So if you're not running a huge enterprise, just looking to bring in a couple of dollars, you wouldn't want to put yourself on the health department's radar for that. If you're looking to make a business of it, then you'd need to go the route of a permit from the health department, a food truck, etc etc.