Well you're right, I misremembered. Also I just looked it up and I think it was actually a Panda and not a Punto (only owned it for a short time around 2009 and it was already close to worthless when I bought it). Still, I think it doesn't change the point much: at 500kg you're closer to a small car than to the lightweight moped for which these exceptions were made...

In the same way, a Panda is a ton. Generally speaking, the lightest you're every going to find in cars is 800kg. I drove a Clio 1 Phase 1, that was 820kg. And let's be honest, it wasn't much more than an engine, seats, and a body. Even a Twizy, which is absolutely nothing is in the 475kg range. Engines are heavy.

But yes, you are closer to a car. if it's truly 500kg.

Daewoo Tico is 680kg and I have seen few of these on the streets (not so common anymore).

Polski Fiat 126p ~600kg

The official maximum weight for a "light quadricycle" is 350 kg- but that doesn't include the batteries in the case of an electric vehicle.

If these are like most electric cars, the batteries are in a flat compartment at the bottom of the chassis in a box design, giving incredible torsional rigidity and a very low centre of mass, so great cornering. They could be pretty safe for the occupants, even fanging it down a narrow European street. However, not so safe for pedestrians. I'm guessing these won't come with ABS or mm wave collision detection emergency brakes; it's one of those items that is cheap to manufacture and install, but the IP and testing is expensive.