When I was still working and wizzing around the country I used to have a Road Angel with a second additional laser detector mounted on the front number plate. Quite a few times particularly on the M6 and M4 I got long range laser warnings of the spies on the overhead bridges as the system seemed quite sensitive. The fixed and mobile camera warnings were very useful too and saved me a few bob until one day near Carlisle I ignored a laser warning and lo and behold got a ticket! Nowadays I drive at a more relaxing pace so don't worry anymore
