The Vespa 400 was built in Piaggio's French factory. The competition for midget cars was fierce though and it quickly became obvious that the car would not become as popular as the scooter. To look at, the Vespa looked something like the Fiat 500 Topolino which had ceased production in 1957. The Vespa was smaller though and only had room for two. The car weighed a mere 370 kg (814 lb) and had a top speed of 55 mph (88 kph) despite its tiny 13 bhp engine. Its fuel consumption was rated at a constant 50 kph (39 mph) as 69 miles per gallon (1 litre per 23 kilometres). This dropped with the foot flat on the floor to 45 mpg (1 litre per 15 kilometres).
The Vespa 400 with its 393 cc engine was available in two versions: the deluxe model with two windscreen wipers instead of one, chrome plated bumpers and nave plates, and better upholstery trim. Sliding windows in the doors were added in 1959 and a four-speed gearbox in 1960. The following year production ceased. The Vespa could not compete with cars offering much more but costing less.