This minute vehicle is not a city car. It is what is generally referred to in France as a sans permis (literal translation: 'without permit') or sometimes a voiturette (little car). This one is made by Aixam, the leading brand. The other main brand is Ligier. The expression sans permis derives from the fact that you do not need a permis de conduire (drivers licence) to drive one of these.
You can drive a vehicle like this on the public roads of France from the age of 14. All you need to do is seven hours of practical training and if your driving instructor thinks you are safe, you will be issued with a permis AM (formerly called a brevet de sécurité routière or 'Road Safety Certificate'). The practical is broken down into two hours on the driver training course, four hours on public roads and one hour of practicing accident avoidance techniques (learning the relationship between speed and time taken to stop, anticipation, how to brake and corner safely...) There is no exam. The theory part is delivered as part of the curriculum at junior high. This permit allows you to drive a quadricycle léger (light quadbike), which is what this vehicle really is. They have two seats and a 50 cc petrol engine. Their speed is limited to 45 kilometres an hour. Drivers are not allowed to take them on autoroutes or divided roads that have more than one lane each way.
The driver education programme is aimed at keeping adolescents safe on the road. The manufacturers of these voiturettes would dearly like to sell them to adolescents or the parents of adolescents, but the truth is they are so deeply uncool and so expensive that I have never seen an adolescent driving one. They all have scooters. The people who actually drive these vehicles are the aged who have never had a full licence, or those who have lost their full licences. Yes, that's right -- you can have your drivers licence removed but you can apply for a permis AM and be sent one automatically by the Prefecture. Mind you, the shame of driving around in a 50 cc vehicle limited to 45 kilometres per hour is probably seen as an added punishment, and you can't do nearly as much damage in a voiturette as you can in a BMW.