DETROIT (AP) _ Since May, General Motors Corp. has been running ads urging people to lease a Catera. ``Who is Lisa Catera?'' the spot whimsically asks.

She didn't exist until Wednesday, when Dr. Lisa Catera showed up as a new character on the CBS drama ``Chicago Hope.'' Executive producer John Tinker says the commercial inspired him to name the character, played by Stacy Edwards, but GM didn't pay for the tie-in.

Still, GM knows a good gimmick when it sees one. The company has started running commercials for the entry-level luxury car on the show.

``For our purpose it was a nice tie-in,'' said Michael Oxman, senior vice president at DMB&B advertising, which has GM's Cadillac account.

GM even trumpeted, ``Catera would be a perfect car for someone like Dr. Catera.''

Sorry. Dr. Catera drives a Volvo.

___