On your windscreen up high with suction caps and have hard wired or into cigarette lighter plug.
For radar guns it works from far coz radar gun have strong signal, but for speed cameras it only works from few hundred meters enough time to slow down coz speed camera very weak radar signal.
In any case when it beeps or starts going troppo slam the anchors on as they (the police) need to have a bit of time to lock you in.