Wherever space is provided for the parking of three or more vehicles in the open, such spaces shall be individually identified by means of pavement markings. No parking space shall be located in any front yard or within 10 feet of any lot line in side or rear yards. No service of any kind shall be permitted to be extended to users of the lot, including automobile service, repair or fueling, and no gasoline, oil, grease or other supplies shall be stored or sold in any such lot or in any garage on such lot. Parking areas shall be screened by a substantial wall, fence or thick hedge, approved by the Planning Board. Generally such screening shall not be less than four nor more than eight feet in height, planted not more than three feet on center.