Historic motor vehicle: means any motor vehicle whose manufacturer's model year is at least 25 years old or any motor which is at least 15 years old and is a make of motor vehicle no longer manufactured; provided, that the motor vehicle has been or is being restored, preserved or maintained as an exhibition or collector's item because of its special historical value or significance, has not been substantially altered or modified from the manufacturer's original specifications and is used on the public highways for the transportation of passengers or property in conjunction with exhibitions, expositions, parades, tours, club activities, or similar activities or events, including transportation directly to or from such activities or events, but in no event used for general transportation. Motor vehicles which are less than 25 years old but which are 15 or more years old and which qualify as historic motor vehicles shall include but not be limited to the following makes which are no longer manufactured: Kaiser, Hudson, DeSoto, Nash, Edsel, Studebaker and Packard.