Not quite, a car is not a place. It is private property (as opposed to on it), technically, it's a private possession which can be in a public place such as on the highway, or in a private place such as your garage. When you are in yourt car on the highway, you are in a public place, when you are in your car in your garage, you are in a private place. Think of your car as a suitcase on wheels. Anything in your car in a public place, is in public - just like it would be in your suitcase.
Lets muddy this just a bit. Suppose it's not an ordinary car but rather a self contained RV (or a Gypsy wagon) parked in a public (commercial or otherwise) campground. The public is allowed access to the campground true, but is the RV still considered a "public place" since in essence you are using it as your home for the period? If so then how is it different from a flat in a "public" complex?