Conn. Gen. Stat. § 21-12: Display of license.

Each such dealer doing business in this state shall display, on each vehicle used by him in such business, the name of the person conducting such business, the number of the license under which such business is being conducted and the name of the municipality where such license was granted, which names and number shall be painted upon the outside of the body of such vehicle in letters not less than four inches in height and two inches in width.