if you specified the amg kit on a normal merc, it came with the badging
just like you get M badges on a bmw with the m packet
Rarely, and this one doesn't even have the AMG kit.
To be fair, I consider myself a car enthusiast but would not think that it wasn't an AMG mainly due to the quad tailpipes and other than that wouldn't be able to name any other differences for that model of S class. The badge looks pretty cool and the car does have AMG parts on it so I see no reason why it should be removed.
Well I wouldn't call yourself an enthusiast if you couldn't spot the differences. The car doesn't have an AMG bodykit, there are no AMG calipers and the biggest giveaway is that the pre-facelift AMG only had a dual exhaust. The badge does look cool, on a genuine AMG, the only parts I can see on that car are the alloys. It's entirely up to jez whether he keeps the badge or not, in my opinion it just looks silly because it doesn't have anything AMG about it apart from the alloys and exhaust tips.