I'm experiencing a very distinct "thumping" noise from the frontend at speeds between 20-25 mph. It's been there since about 2K miles on car. I now have 10K miles.
I originally thought it was an out of round tire or brake pad rub etc. Had roters turned and tires checked - nothing. Car rides smoothly at all speeds, no pull or shaking etc. despite sound. The vibration is beginning to be felt through the brake and accelerator pedal.
Has anyone else experienced something similar?

 

As a very rough guess, I'd say something on the body, perhaps part of the front spoiler, or front lip, has worked it's way loose and is banging on another body part. You may be able to lacate this by getting underneath or (better) by hoisting the car on a lift to find the offending part.
I'd suggest a trip to the dealer, explain the problem and let him hoist the car to discover the probem. It could be something more serious too, such as a suspension part that he can locate easily. Good luck bro. I think you've prolly put up with that 'thumping' long enough.

<font color=red>GSM</font color=red>