Being such a perfectionist, i decided that the satnav in my 2012 XF was somewhat lacking so I decided to use Google Maps on my Samsung S8+ instead. The thing is it wouldn't work properly in the car - misdirection's, inaccurate figures, slow updating. My conclusion - The £600 Samsung S8 has a naff GPS receiver. My solution - I buy myself a £250 top of the range Garmin Drivesmart 61 satnav. It's fantastic and works really well - except in my XF, misdirection's, inaccurate figures, slow updating, sound familiar? So I borrowed a friends TomTom 8200, guess what... misdirection's, inaccurate figures, slow updating when used in the Jag. Being the inquisitive type I played around a bit and discovered that when the XF's screen is on, all these devices completely lose their satellite reception, you can actually watch each satellite drop off one by one. Disable/blank the screen and they all instantly reconnect and work again. I can leave the radio on, leave the XF nav running and everything's fine but as soon as the screen comes on, dead satnav's. Before I ask the local priest to perform an exorcism on the car, I though I would ask you geniuses if you've experienced anything like this. Before you ask, no drink or drugs were involved.