"Dealing with Box-Like Objects" is the 3rd in a series of UV Editor Tutorials.
http://www.awbenson.com/tutorials/Carrara_UV/UV_3.htm
This tutorial teaches about how to split up a model by using Shading Domains. Each domain's face is then placed upon a metal-box texture map, overlapping the prior UVs so that the whole box is mapped to a single square
Screen shots are taken with C5P Beta, but this tutorial can be done with C3 and above.
If you have any questions, please post them up.
Andrew
AKA: AWBenson
www.awbenson.com