Although it doesn't 'boil' the water, it's very possible. I purchased a tracer, I suspect the water pump.

It's got to be a head gasket slowly letting go, if there is no sign of a leak under the car.

Every 3 months I lose 1 l of antifreeze ... where? The oil is black, not emulsified, the smoke is colorless and only during brutal acceleration is it black so there is a crack in the cooling circuit. Where could it be?

The new thermostat (Wahler) is not working properly. It takes too long for the water to reach 3 dots.

There are still some really great micro-cars available in Europe, but the math ain't mathing on these. I would LOVE an ultra-compact EV to have in the driveway for convenience, but only if it comes with a truly affordable lease.