Open Source has been tried on physical objects... (Score 1)

...according to Malcom Gladwell:

"The Bakeoff"

http://www.gladwell.com/2005/2005_09_05_a_bakeoff. html

The article is a discussion about the use of programming methodologies (traditional, open source, "extreme") to create something that isn't software -- in this case, a cookie.

It's n=1 but the conclusion is that there are some good reasons why an expertly run traditional team is better at producing goods, even if some of the alternate programming methodologies are sometimes better at producing code.