Many modern cars have a time delay feature, first introduced by Cadillac in the 1980s, called "retained accessory power". This allows operation of the windows and some other accessories for ten minutes or so after the engine is stopped. Another feature is the "express-down" window, which allows the window to be fully lowered with one tap on the switch, as opposed to holding the switch down until the window retracts. Many luxury vehicles during the 1990s expanded on this feature, to include "express-up" on the driver's window, and recently, some manufacturers have added the feature on all window switches for all passengers' convenience. This is done by activating the switch until a "click" response is felt.