I have recently started getting a cyclical vibration at speeds around the above. It repeats about every five seconds. As an obscure reference, it is similar to what you get in a twin-engined plane when the prop speeds are not synchronized? Is something like this as simple as needing the wheels re-balanced? (This is with the CLK500)

Momo

__________________
1990 500SL 65k km - until May 11 2004
2004 E320 4-Matic wagon
2004 CLK500 Cabrio from May 11 2004

If it has started recently, I would suspect balance of the tires first. Then check the propellor shaft flex discs just in case, although it is likely they are ok since it is such a new car. Most the time when I get any vibrations it turns out to be the tires, not just balanced, but bad, I had a bald spot on my right rear, they tell me it was from peeling out too much! ha ha.. Good luck!
Brian

__________________
Brian W. Heitman

www.MBCA.org/northtexas

Join MBCA!!!