Hi Antony and welcome to the club :D The cup holder is held in purely by friction and can be simply levered out. In fact, a lot of S Type drivers leave the cup holder out as the space makes a useful cubby hole. The workshop manual is readily available. If you PM me your e-mail address I'll send you a copy. It is some 6000 pages so very comprehensive. There was never a Haynes manual for the S Type. I can also send you a copy of the driver's sat nav handbook as well, although, from what you describe it sounds like your sat nav disk may well be goosed. As far as your engine problem, being a diesel driver I cannot comment but I'm sure somebody will in due course..