The term CAR OPENER can be broken down into three crossword solutions: ECONO (5 letters), KEY (3 letters), and RENTA (5 letters). ECONO is a term used to describe something that is economical or cost-effective. KEY is a noun that refers to a metal device used to open or close a lock. RENTA is a verb meaning to pay for the temporary use of something. Together, these three terms refer to a device that is used to open CAR doors without a KEY, usually by remote control.