Do you mean a shorter gear shift? Or a quick shifter, as in full throttle change gear without using the clutch.
If it's the former, check out the black box's thread, I'm sure he moved his in the car with a custom made box.
If it's the later, I've never done one on a car. I did one on a bike years ago, it was a cow of a job to get set up right. Would work better with a sequential box anyway.
If what you ask for is short-shifter, then you can look on the top of the gearbox. There is a "moon" form like plank, which is connected with one of the selector cables. The connecting point is ball joint, you can cut it and weld back a bit off position to shorten the movement. I don't know if this is common solution, but I have used it on mine and it works well.
Hope that you can understand by my bad explanation.