Other than the "Title and tag at point of sale" the rest of the restrictions on cars are only if I want to use it on a public road. I can use it on private property and at the track without any of those other requirements. I can buy any car I want and can afford. Off of public roads, I can possess and operate any car I want without restriction, without a license, without insurance. I doubt guns will ever be as unregulated (at least in MA) as cars are.