In fact, this problem CAN BE major - the cable connecting the clutch pedal to the clutch can get a bit loose (Fiat's using a plastic screw with a smaller metal screw on top, not very solid looking), and the car doesn't fully separate the gearbox from the engine when you shift gears. In the early stage, there's no clunking noise, just resistance on the gearstick - the noise first appears when you try to put in reverse, then sometimes on first and second. I nearly had a horrible incident because of this: I started overtaking a bus that was standing in the busstop, and a pedestrian ran out in front of the bus - I started breaking, but the road was wet and I started sliding, so I tried to shift down from 3rd to 2nd (the regular stuff), and all I got was a loud "krrrrr".... Even worse, I couldn't put it back into 3rd. Luckily, after hearing the noise the pedestrian jumped off the street, and I missed her, but continued sliding along, in the wrong side of the street. I took my car to a Fiat dealer and got horribly ripped off in the process, as usual.