The Piaggio Vespa 400 is a small car with a rear-mounted engine, produced by ACMA in France in 1957-1961. Three different versions were sold and it: Luxe, Tourisme and GT.

The car was unveiled to the public in September 1957 at a presentation in Monaco. The Vespa 400 was a 2-seater car with space behind the seats to accommodate luggage or two small children. The instrumentation was very basic, with just a speedometer, low fuel warning lights, high beams, dynamo charging and gauges. The car was powered by a 0.4-litre 2-stroke I2 engine with 14 hp (10 kW).