Not sure what it's worth, make me an offer.
I took some pictures today, but can't find my camera cable.
I do have the parts diagram that shows how it goes together, see
http://rides.webshots.com/photo/2479796300043637851dvqpey The diagram for the standard tank is also loaded in that album, and the aux tank and parts is visable in some of the kit pics, but hard to really see.
It looks like the line go through the existing fuel tank access hole in the trunk, so no major surgey required. Might have to drill a few holes for hold down bolts though.
I have the filler pipe (looks like it's different than a single tank) and the tee hose. There's a smaller (~1/2") line going from the aux tank to the main that I think I should have but can't find. I think it's not a molded hose and could be replaced with 1/2" fuel hose. There's also a vent hose you'd need to put together, but it's just 3/16" (maybe) line so that's simple.
~John