You sure you don't mean MB in size? The only thing that should be single-digit KB in size are roster files.
For context, a carfile with a 2048 car texture and a 1024 crew texture should be hovering right around the 1.5-2.0 MB size when the textures are compressed, and that's already somewhat pushing the limits of the game. Anything larger than 4 or 5 MB iirc can break the game, especially if the car textures are high resolution, and uncompressed.
These are the cars that have problems.https://drive.google.com/file/d/1ljHlJt4bO_lWcPvptxVtwaFZUWe9kfsU/view?usp=sharing
Yeah, I try to record the race but not only the some of cars has no paint, the windows are black for some reason.