The mesh file is part of the 3D model, contained in the car's mas file, for some reason the game can't find or can't load that gmt file. It is called via a path in the car's gen file. If you have moved or renamed any of these files, undo that. Sometimes this is a temporary glitch, load a different mod and exit the game, start it again and try the problem mod again. If the problem continues the easiest fix is to reinstall the mod. Making a guess, "GY_LF_LOW" could be "Goodyear, Left Front, Low (res)", so is common to all cars in that mod
Not a likely problem with modern systems, but this error can also be thrown if many cars are loaded and the memory allocated to the game is exceeded, so there's no memory in which to load the file.