Sleeper Car Lyrics Follow

A sleeper (US English) or Q-car (British English) is a car that has high performance and an unassuming exterior. Sleeper cars are so called because their exterior looks similar or identical to a standard or economy-class car. In some cases the car appears worse due to seeming neglect on the owner's part, typically referred to as "all go and no show". While appearing to be a standard or neglected car, internally they are modified to have higher performance levels. The American nomenclature comes from the term sleeper agent, while the British term derives from the Q-ships used by the Royal Navy.
In the February 1963 Motor Sport magazine editor Bill Boddy said "the modifications carried out by Lotus have turned [the Lotus Cortina] into a 'Q' car par excellence". The British film The Long Arm (film) (1956; aka The Third Key) mentions a Q car (unmarked) patrolling the city by night, indicating that the term was in use among UK law enforcement at least a decade earlier.
In July 1964, British magazine Motorcycle Mechanics carried an announcement from editor Bill Lawless of the use of two police 'Q–cars' – a black Daimler SP250 sports car and a green Farina Austin A40 – patrolling the A20 between London and Maidstone, Kent.

Source: Wikipedia