All 986's carried the computer, but lacked the fourth stalk (which in conjunction of the computer being switched on consititued the "M659 option" from the factory). So you would need to pull the steering wheel assembly off to swap the stalk assembly, plus pull the main dash cluster to add some of the wiring, then have the system "switched on" by a Porsche dealer that is willing to do it (many will not, supposedly under orders from the factory), and actually knows how to (many do not). One thing that will still be missing, if memory serves, it the fancy dot matrix display that came on the cars with the factory option, but your standard display will still work, just not look as cute.
