Ok, well ive been really testing my car lately to get to the bottom of this vibration shit, because its very annoying when traveling somewhere that everybody is doing like 80, and i cant because of the vibration, anyways, the car will start to vibrate REALLY bad, right around 74mph, and will not stop if i accelerate, and if i let off it vibrates really bad for like 1-2 seconds then is ok, but as soon as i hit right around 74+ it does it again, steering wheel does not shake, but i can feel it in the clutch pedal, shifter seems to shake quite a bit, but maybe it just shakes alot anyways, and i can somewhat feel it in my seat,

Anybody know wtf is wrong? its really bothering me..