With the awesome exception of the Pagani Huayra:

http://www.pagani.com/huayra/partners/aspa.aspx

"Even the car's name tag positioned on the rear bumper, is carved in a 24 hour process from a solid block of aluminium. It is the Pagani way of reassuring its customers that their cars are built to their own standards exceeding the highest in the industry."

Great example really. Basically highlighting my message; it can be done (and can be awesome- machined parts are top-quality) but the Huayra costs $1.3M.