Since its launch as a '99 model, Nissan Motor Co. Ltd.'s Xterra sport/utility vehicle (SUV) has been a marketplace winner and symbolic of once-stodgy Nissan's ā€œnew attitude.ā€ But after a couple of outstanding years, Xterra U.S. sales through the first half are down 13.8% from a year ago as tough new competitors, including the hot-selling Ford Escape, Toyota RAV4 and the new Jeep Liberty, chop away at the successful Gen X-baiting SUV's market share, Nissan sales and product executives know the going only will get tougher in one of the market's hottest segments. So for the '02 model, due to go on sale this month, Nissan plans to respond to the new competition by producing more Xterras in XE trim and fewer of the high-line SE models. Moreover, Nissan says Xterra packaging and content will be revised so that better equipment will be offered at a lower price.