I got to listen to an SDL from a very weird angle today, at least for me. On the highway at 70 you can hear the turbo outside and it does sound like a Mack.
I was driving alongside my brokers SDL today in a CLK550 cab with the top down. I was right next to the fender, and got to really hear the engine and turbo working from an angle that I am not used to.
Cool, never new my car sounded that cool, can't really hear much with the windows up and the radio or phone going.