This photo was sent to my Facebook page and shows a group of rescue workers lined up in front of their vehicle. It's thought this may be from the Derbyshire area. The car is probably a pre-war American import that has been requisitioned by the local authority and converted for the use by a rescue squad (there's a ladder and stretchers on the roof). Unsure what the make of the car is - some think a Packard and others have said an Auburn.
News about interesting insignia, ARP related info and period photos that turn up.