Scanning a chassis plate into a .dxf file?

[JThiessen]

I think Canvas used to be able to output a .dxf file from a scan, but it likely will loose some accuracy - but what you are doing is really not an accurate way of obtaining geometric data anyway. I used to use it to export pictures for etching on a laser.
Where do you live (city)? If its larger enough, there may be a company in the area that does rapid prototyping, and they have 3D scanners, and may do one for you. However, the files they output are huge, so just be forewarned.