Clk 2000. The car has developed A whirring noise and it get louder the faster I go. It starts at 60kph then in stages at 80 and 110kph getting louder all the time. Any ideas before I go to a garage?

 

I had the exact same issue in my clk. Turned out to be the rear driver side tire. It had developed a ridge/dent like trench all around the tire and obviously upon impact and forward motion with the road.. i got a whirring noise.. Check your tires dude, could be as simple as that. Worked for me..

And before I checked tires, the dealership couldn't diagnose it, they wanted to change barrings, disc brakes etc etc. Simple tire issue. Hope it's the same for you, let us know!