No franchisor shall enter into any franchise for the purpose of establishing an additional motor vehicle, combination motor vehicle and trailer, motorcycle, or trailer dealership or warranty repair service facility, in any community in which the same line-make is then represented, unless the franchisor has first established in a hearing held under the Motor Vehicle Industry Regulation Act that there is good cause for such additional motor vehicle, combination motor vehicle and trailer, motorcycle, or trailer dealership under such franchise, or warranty repair service facility, and that it is in the public interest.