I suspect we'd prefer to get it back here for checking. I got exactly this noise when the mk2 went into the miata, but this was because the grounding leads were still fitted (and *very* hard to get to - unbolting access panels & that sort of thing). With the leads removed, it all went away.

If you're still hearing it though, it sounds like a unit fault. Mail Rob and ask him about getting it collected.

Hugo