This episode's headline: Used Car Rule: Too Tough or Too Soft?; Feldstein Reflects; To Catch a killer; ""A Prairie Home Companion"". The guests include In Washington: CLARENCE DITLOW, Chairman, Public Citizen; MARTIN FELDSTEIN, Council of Economic Advisors; JAMES STEWART, National Institute of Justice; In Chicago: CHARLES NICHOLSON, Used Car Dealer. Byline: In New York: ROBERT MacNEIL, Executive Editor; In Washington: JIM LEHRER, Associate Editor; Reports from NewsHour Correspondents: ADRIAN BROWN (Visnews), in Vienna; BRENDAN HENEHAN (KTCA), in St. Paul