Ford Motor Co.'s Mercury brand launches a 15-second teaser spot on Friday for its first sport utility vehicle, the Mountaineer. The teaser, part of the estimated $40 million launch for the vehicle, appears on network and cable through May 22. The spot, from Young & Rubicam, Detroit, shows a deserted road and a "watch for falling rocks" road sign, then a placard with the words "1997 Mountaineer coming May 23." That day starts a major TV and print blitz. Two TV spots will air more than 1,000 times on network and cable through June.