Good posts and Helmut has it in a nutshell (d*mn, he's good!). The requirement is that you audit each manufacturing process, which is a little ambiguous, IMHO. Does that mean the transforming process (like stamping, welding, painting molding etc.) or from the moment the raw materilas arrive until they are shipped? - one could say that they too are manufacturing processes. I have elected to take the same approach as Helmut and follow the control plan, normally from the placement of materials at the 'machine' to the point of a finished part, with no adverse comments from external auditors.
The LPAs don't go far enough and although the authors of the LPA guideline state that they can be used in place of auditing a manufacturing process, they usually don't follow the 'process approach' and one thing often overlooked is the fact that the auditors are often not trained in the use of the core tools, which internal QMS auditors have to be - especially if they are to audit the manufacturing processes!