So I'm a big fan of auto racing and consequently, I'm pretty big into racing games. I grew up playing stuff like Gran Turismo (I've been a fan of the series since the original came out in North America back in '98) the various Need For Speed games, the Tokyo Xtreme Racer series, the Initial D games, Wangan Midnight: Maximum Tune, etc.
While there is certainly plenty of modern racing games to choose from these days, they are often instance-based and take place on closed circuits rather than an open world. To my knowledge, there's been very few true MMO open-world racing games. The most recent such game was Need For Speed: World, but unfortunately EA shut down the game servers earlier this year and I have yet to see another game quite like it.
I know there's stuff like Forza Horizon and GTA (although GTA isn't just about racing), but these games are lobby-based and are not true MMOs. In contrast, NFS: World only had 2 servers, one for Europe and another for the US. The world was a giant, persistent city in which you could encounter thousands of different players while cruising down the streets in free roam mode.
There was tons of different real-life cars to choose from. You could tune your car by upgrading the engine, forced induction, transmission, suspension, brakes and tires. You could apply a whole assortment of visual mods such as bodykits, spoilers, custom wheels and vinyls. Everyone had a car that was uniquely tailored to their specifications.
You could challenge players to private races on a closed track or just race them unofficially right there in free roam. Sometimes you'd encounter entire crews cruising down the road together. There would be groups of people hanging out at intersections doing donuts/having sideshows, random guys drifting on the winding roads going through the mountains on the edge of the city, people RPing as cops with police vehicles chasing speeders, etc. At any given time you could log in to find a city teeming with racers. The game felt really "alive." It was just a really special experience that seems to be missing from other modern racing games.
So, does anyone know of any other open-world MMO racing games that has similar features, preferably with at least a semi-realistic driving/physics engine? If so, I'd love to know about it!