I did it on my 98 8 years ago. See this thread: https://www.jaguarforums.com/forum/x...o-today-38499/

I've never been thrilled with the look so I'm thinking about adding this: https://goo.gl/Qv9weK

To do the job you need to remove the shift surround and center console and then the fascia.

 

 

I just went through this research on one of my other vehicles, and found a couple of single din units at Amazon that had small screen. This one may fit, but you would have to measure your dash area- I don't have an XK8 ( yet).

One newer style that I have installed and like is an Android Radio. It has a separate face unit from the actual radio, connected with a flat cable 12" long ( extensions available). They come in different screen sizes. One that interests me is the 8.8" dia. screen, which is about 4.2 x 9.2 in actual size ( about 1/2" thick). I'm thinking of mounting this where the 3 gauges are located, and re-locating the gauges to the radio location. The "new" radio box may fit where the old radio was located, with the extension cable running up to the screen. Would require making a couple of panels ( one for the gauges, one for the screen), but it gets the screen up where you can see it. You can even mount the screen using a couple of MagDaddy Panel Magnets- I tried them and they do not affect the screen. Probably a good time to upgrade the gauges so they are fully functional too! XK8 / XKR / XJ RealGauge - TheJagWrangler

Available direct from Joying, or via Amazon.

 

The part from ebay will fit a single DIN unit so not sure what the NAV options would be at that size. I rarely use the NAV in my other cars when if I need it my phone generally does the job better.