Hi guys, i have bought a lovely 1999 S type 3.0 V6 SE its amazing i love it! the only thing missing is a sat nav,I have managed to find one on ebay the seller is selling the complete sat nav ,i was wondering would the wiring loom be already in the car ready to just plug and play? would be very grateful for any help as im a complete novice here! thanks Steve.

I swapped out a non operative CDC in the boot, which I guess is c20 year old tech as well. But the replacement unit was only £30 and it works well.         

I suspect the wiring is sitting there waiting, as unlikely they'd use a different loom just to add nav, so if nav was an option on your model year you should be OK. But I can't confirm this categorically, hopefully someone can.

Ron has a good point though, can the old nav be updated and suchlike?

Good luck