As a new Euro owner I've read these threads with interest. To me it sounds like pinging and even my wife commented that it was pinging after her first drive, and she's not mechanically minded at all.

Anyway, what ever it is I asked for it to be written on the invoice for the first service so that at least it is documented. The invoice also says .. "Checked and found this to be a normal noise, we have spoken to Honda who are looking into the issue. This noise will not cause any damage to the engine".

The bottom line is that the noise spoils my enjoyment of the car. My 2 cents worth.

Cheers