The Felber Autoroller T 400 is a three-wheeled microcar with a rear-mounted 398 cc Rotax two cylinder opposed twin, two stroke 15 PS engine.[1] The cars have an unusual seating arrangement, with a small child-sized seat behind the driver on the left and a conventional passenger seat diagonally behind and to the right.[1]
A. Felber & Co were a well known manufacturer of motorcycle sidecars, based in Vienna, Austria.[1] The Autoroller was designed by Ernst Marold.[1] From 1952 to 1953, about 400 units were built in two versions, all of which were painted light green using a standard paint then used for machinery which was cheaper than car paint. Early models had cycle-type mudguards that swivelled with the front wheels, later models had fixed wings.[1]