Public garage, automobile repair shop, motor vehicle service station, car wash or other establishment where motor fuel, lubricating oils or motor accessories are stored or motor services are rendered, except that no public garage, automobile repair shop, motor vehicle service station, car wash or other similar establishment where motor fuel lubricating oils or motor accessories are stored or motor services are rendered shall be located within 300 feet of any property upon which a church, school, hospital, theater or place of public assembly seating over 50 persons is located. Said distances shall be measured on a straight line or air line from the outer boundary or property line of the lot containing the proposed use to the outer boundary or property line of the lot containing a church, school, hospital, theater or place of public assembly seating over 50 persons, public garage repair shop, motor vehicle service station, car wash or other establishment where motor fuel, lubricating oils or motor accessories are stored or motor services are rendered. No outdoor storage in connection with any of the uses mentioned in this subsection shall be permitted, except that the outdoor storage of small utility trailers which can be attached to motor vehicles and which have a load limit not in excess of 2,000 pounds, commonly known as "U-Haul-it trailers," shall be permitted at service stations.