Jam sandwich
A jam sandwich is a sandwich containing jam.
In British English slang, a Jam Sandwich is a police patrol car. The term came into common use in the 1970s, when police cars changed from the traditional dark blue to white with a broad fluorescent orange stripe along the side. This colour scheme is reminiscent of jam sandwiched between two slices of white bread, hence the name. The slang was popularised on such TV shows as The Sweeney and Minder, as well as spreading through the use of CB radio. It is still in common use.
