Try a temp fitting to test before sticking it down.
Its supposed to have a clear view of the sky and be placed horizontally and normally with the cable facing front or rear wards.
Most navs will self calibrate after a cold start, but mat take a few hours driving to lock on properly.
I've previously fitted 3rd party GPS antennas.....
Ontop of the dash anywhere along the line by the windscreen.
Top of the windscreen above the rearview mirror, the black bit should allow more signal through.
Behind the dash sitting ontop of the glovebox or ontop of the radio, so under the plastic, but right at the top..... this is a nice hidden solution, but anything placed ontop of the dash will block the signal.
Above the headlining or anywhere behind sheet metal will not work.
Some tracker firms even fit them behind the front bumper plastic....
So its trial and error and depends on the quality and sensitivity of the navi/antenna as well as GPS signal strength in your area.
Just start off with it sitting ontop of the dash either centre or side. (Below the old tax disc position)
@Absolut5
@travelvolts
Anything to add guys or further advice? (Trade members)