All materials are delivered to the prefab factory, in bulk, the prefab house is assembled complete in about a week (including internal finish), and the house is delivered in a single delivery.
If you locate your prefab factories along convenient bulk shipping routes (railroads, rivers, canals) and order houses from the closest factory, you've reduced your shipping costs considerably.
I do really like this idea. I believe something like this, with some prefab parts that are automatically mounted could really get us one step closer to something like what Jacque Fresco envisioned http://en.wikipedia.org/wiki/Jacque_Fresco. I especially like his automated building tech which could combine prefab with foundations etc being built by a machine like this. http://thevenusproject.com/technology/construction
This manufacturer says No Manufactured Home built to the new Florida Building Codes implemented in 1999 went down in any of the hurricanes of 2004-2005.
http://www.leecorpinc.com/leecorp-faqs.htm#9
That's just the first interesting link I found searching on "hurricane double wide", and of course it is promotional, but what is important is whether the building is built to stand up to the storm.