The car is a 2008 XJ8 Vanden Plas. So after resolving my navigation issue with a firmware update, thanks to NORRI, i now am ready to tackle another problem I have incurred. I changed my clock light bulb to the white t5 led bulb as i did in my 04 xj8. The only difference in this bulb change is now the windows dont work if the dimmer is switched to full blast or if the interior lights are on! The navigation panel buttons or clock light dont light either when the interior light is turned on! What have i done? Anyone have any ideas? Thanks guys!