Ohh I see, this is rather easy. I did this for ship unit in strategy prototype.
For wheeled vehicle I would do like this - You know the direction where your unit is currently looking and you already storing the location where it needs to move. On every frame, calculate needed rotation by interpolating between unit current rotation and FindLookAtRotation(Unit_location, Target_location). Speed of interpolation will define speed at which unit can turn. Stop interpolating when difference between rotators is smaller than some epsilon.
For something like a tank, you can first measure how much is the difference between your current rotation and rotation to target. If difference is small, then threat is like vehicle. If difference is big then do a “neutral turn” first - rotate tank in place until faces the target and start driving only after that.