If you decide to use Add a A Circuit, both fuses need to be installed for it to work. Remove the panel under the glove box, when you do this, you will see a white looking handle by the floor boards. Not really a handle but a white square cut out space where the cover clips into. Use that white handle to tap a screw into it for your ground.
2016 Discovery Sport Santorini Black Metallic, HSE Package, HUD and Park Assist Pack, Climate Control Pack, 18" Inch Black Design Pack, Audio Upgrade Pack, Driver Assist Plus Pack, Protection Pack