I have had my Mazdaspeed3 for 6 months. Just the other day i was driving to work and started to notice that upon acceleration a stop that my switching of 1st to 2nd and 2nd to 3rd gears i feel and hear a little knock below my left foot and along the left side of the car. This knocking goes away when i reach 3rd gear. This does not affect the accel. but just has me worried that maybe something is wrong with my clutch or transmission?