I have a 99 2.5 L and my shifter cables are adjustable. I know this because I just installed a new shifter and marked the cables so I didnt have to readjust them.
look Porschedoc also wrote.
With a marker or paint pen, mark the relation of the cables to the holders for easy of reinstallment. This is a very important step, and you will not have to make any adjustments to the cables going back together if you mark them correctly. Once they are marked, you can simply pull the ends out of the spring holders.