Where's best to go for some good offers on Mercedes Benz cars?

I don't know about the UK, but in the US, the Merc dealers pretty much tell you "take it or leave it" and they don't deal much on the prices, because they feel if you're serious about buying a Merc, you'll buy it for a couple grand more than you would ideally pay because that couple thousand dollars shouldn't be a deal breaker, or else you should be shopping at a different marque like Toyota or Ford. Maybe in the UK it's different, but I thought I'd share what the experience is like in the US.