TM:PE (Traffic Manager: President Edition) has a setting for more realistic parking: https://doc.tmpe.me/gameplay.html#parking-ai

I don't know if it strictly mandates having physical space persistently for every car that exists in the city, or whether cars still somehow spawn and despawn dynamically under some circumstances.

Edit: Looks like the car despawns if an attempt to find a parking space close enough to destination fails ten times.