My car has been at the mechanics for more than a week now, I visited him today and the problem still exists.

I sense a vibration under my feet on low speed and RPM, the vibration disappears when I'm driving at 140+ km/hr, I really noticed the problem when I had 4 friends with me in the car, the vibration almost quadrupled when that happened.

So basically the more weight there is in the car the higher the vibration which is only noticed under my feet and in the gas paddle.

Any help or comments would be greatly appreciated.