That looks like a really shiny after-market exhaust, which might add something to the smiling face factor!
And if you aren't wanting more power you might as well just keep it - at least until you do want more. :lol:
You're right, the MR uses the same S54 engine as the E46 M3 and they certainly do sound fantastic, but running costs for an M would be on a different level to your current car.