Which company is currently responsible for the maintenance and spare parts of this car? Will there be spare parts available in the future?

The accessories should be available.

Nissan is fine; it has the same engine as the Mercedes-Benz GLB.

Looking for Renault in Beijing? They supply parts, so there's no need to worry about parts availability.

Even within the warranty period, going to Nissan for maintenance and repairs still costs money.

Although Renault has exited the Chinese market, it hasn't assigned a specific manufacturer to provide after-sales service for maintenance and repairs. However, this car is quite similar to the Nissan Kicks, and many parts are interchangeable. So, you can also go to Nissan for maintenance and repairs.