I know that beammp and beamng are different things, but it'd be nice if cars wouldn't freeze the game to load in. This would 90% help beammp, and only 10% help beamng, but it'd be a nice olive branch to a large portion of the player base. I'm aware that this would probably make cars take a bit longer to load cars, but I feel that's a fair trade off. If it is such an issue, then it could be an option to turn on or off. I also know that there's options in multiplayer to set updates to be clicked to process them, as opposed to be automatic, but that's still an issue if you're doing a long race, or you're not wanting your play session to be interrupted. I'd even be happy with the ability to cache certain cars in ram if need be in options.
I'm curious myself why the long loading times are a thing, if we have seen mods that can spawn props instantly. Looking at a file that spawns a player vehicle, I see that aside from spawning the car normally it also executes some torqueScript functions, maybe that's a bottleneck? Edit: Nevermind, I checked how said mod works, it spawns the prop beforehand and then just teleports it so it looks instant
game in general could use more optimization all round, dunno why things like this haven't been resolved completely yet. Game's almost 10 years in Early Access!