Dependant on the type of fitting I'd recommend sticking it on the dash itself and you'll most likely need a cig. lighter extension mounted by your left leg too (unless rear passenger is navigating )
It fits nicely to the windscreen to the right of the dials, good thing with the Stilo windscreen and dash you can mount the Sat nav and it hardly obscures your view!
Thankfully a sig charger came in the box, got the traffic receiver too!