I saw a post some time ago that said there were a couple of ground points on the frame, somewhere below the master brake cylinder. I can't find anything there. Has anyone seen one? The closest I'm aware of is under the battery tray, but that doesn't sound like it.

 

Why do you need it there?

Just sand some paint away and take a bolt to one of the pre threaded holes in the subframe and use those. Or you can use one of the tranny bolts.