To answer a couple of emails - here's some information on the 3 motorized rail cars the WW&F rostered.
The largest was a 1917 Model T Ford 3 door touring car that Manley Glidden converted to a track inspection car in 1919. It was unique in two-foot railcars because it had it's own turntable. The equipment allowed the operator to turn the car anywhere there was enough side clearence. The car had a convertible top which was replaced at some point in it's life. In 1930 the car was damaged in a derailment and was rebuilt with a closed body. The closed body was a rare center door type. The center door (2 door) type was designed by Ford to market automobiles to people who were used to the centered door on a carriage. The closed car body was used until the end of operations and allowed for operating later into cold weather season. There was no heater but the crew would put a lit lantern under the windshield to keep ice from forming on the glass. If the car sat out in bitter cold weather the water was drained from the engine and radiator. The next time the car was to be used, a pan of hot water was put on the stove to pour into the cars radiator. At times the engine oil was also drained into a pan and warmed on the stove to pour into the engine block the next day.
The second car was called "the foolish four" because it ran very fast. It was powered by a front fly-wheeled 2 cylinder marine engine and had a drive belt to the rear axle. The car had a two section wind shield.
The third car was the size of a hand car and was powered by a McCormick-Deering one cylinder flywheel engine. There is a good photo of it at North Whitefield, see page 103 of Vol IV Narrow Gauge in the Sheepscot Valley. The car was driven by a flat belt off of the engine's cam. The belt's tension was controlled by a lever that moved an idler pulley which tightened the belt so it would grab the cam on the axle. The car did not get turned because the hit-and-miss engine would run in either direction.