I took the dash apart on my Euro R which comes with the Premium Sat Nav Japanese Head unit (39050-SEA-9410-M1) as opposed to the UK one which is usually 39050-SEA-E450-M1 (or sometimes labelled as 39050-SEA-E810-M1)
It also has 8 speakers as per UK Premium cars (4 x door, 2 x Tweeter and 2 x 6...