Jay Leno has a 3D scanner and printer for his Garage. It looks like he (his people) uses it mainly to do rapid prototyping for parts that are no longer available and have to be fabricated. He scans the original, prints it plastic (mostly) to test fit and function, then uses it to fabricate the actual part. Below is a link to one article discussing it:
http://www.jaylenosgarage.com/extras...y-old-parts-1/