The box exporter is not the way to go with a model of a Ferrari. You'd be better off learning how to make scuplties - look at some of the great SL cars in the WIP section.
Anyway, your model is probably too big and not centered around the AC3D origin. The box creator takes the bounds of each shape and makes a box from it. Each box must be less than 10x10x10. If you scale the whole model down, you may get better results but, as I said, I don't think it's a suitable way to build a Ferrari
