The provisions of this chapter shall not apply in respect to the use by residents of this state of motor vehicles and trailers acquired and used while such persons are members of the armed services who are stationed outside this state pursuant to military orders and residing outside this state. However, this exemption shall not apply to members of the armed services called to active duty for training purposes for periods of less than six months and shall not apply to the use of motor vehicles or trailers acquired less than 30 days prior to the discharge or release from active duty of any person from the armed services.