Clutch problem
 

Well, I am having some issues with my '05 2.3 mazda6.
It drives ok, but in stop and go traffic, if I don't rev it enough when I let out the clutch it shudders and or grinds a little. If I rev it and quickly let out the clutch then it's normal.

My car wasn't maintained very well before I bought it (it had almost no oil) so it could have bad tranny fluid. Would that be enough to cause this, or do I have to get the clutch replaced?

What's the mileage on the car? Clutch could be worn.

Almost 70,000. i bought it in october and don't know if it was ever replaced or not.