Here's the two options: Imgur: The most awesome images on the Internetpics? id go with b and leave the stock wire where its at, as long as there's no big differences in metal between point a and b. i.e. a panel with low contact, a weld, change in pieces of metal.
when you say clamp it in there use a ring terminal closest to the body metal as you can get and sand it down well. ive seen people strip their wire and just put it under a washer, use a terminal lol
"A" as a note is across the engine bay, next to the battery. (My alt is located on the bottom left side of the engine, woohoo)
And yes, by "clamp" I did mean sticking the terminal between the plates. Everything is a mess under there now but I'm going to take a wire brush and a grinder once I get going at it. Only issue with doing B is going to be protecting the wire. I'm, uhh, missing 80% of my underside plastics. You know of any particularly weather/erosion proof heat shrink?