DaimlerChrysler says it will become the first manufacturer to unveil a diesel concept car that will meet more stringent pollution rules and get higher mileage than diesels now on the road. ... Some environmentalists reacted with skepticism to the Daimler car, noting that manufacturers often introduce flashy concept cars that never make it to the production line. They also said the country would be better served by companies making more gasoline hybrid vehicles because they pollute less than cleaner-burning diesels. "The auto industry is trying to convince the car-buying public . . . to reject better technology like hybrid cars,"...