All provisions of this chapter shall be liberally construed to the end that deceptive practices or commission of fraud or misrepresentation in the sale, lease, barter, or disposition of vehicles in this state may be prohibited and prevented, and irresponsible, unreliable, or dishonest persons may be prevented from engaging in the business of selling, leasing, bartering, or otherwise dealing in vehicles in this state and reliable persons may be encouraged to engage in the business of selling, leasing, bartering and otherwise dealing in vehicles in this state: PROVIDED, That this chapter shall not apply to printers, publishers, or broadcasters who in good faith print, publish or broadcast material without knowledge of its deceptive character.