Well this is probably going to sound confusing but, it means that the verticies on the model aren't at 0, 0, 0 in respect to the part.
Now I understand that means nothing to you
so to see what I mean, hide everything except for the bonnet/hood and using the movement tool, select it and use the numbers in little text bars at the bottom to move it to 0, 0, 0
Then select the hood, put it into verticie mode and select all the verticies and do the same thing *using the numbers at the bottom to manually move it to 0, 0, 0*
It should have moved a little because it wasn't actually at 0, 0, 0, now just move it back to where it was before *not in edit mode* and you're done
The easiest way to get it back to where it was before is to copy the numbers from the bottom, before you move it. *put them in a notepad or something*
