Ford creates a stir among suppliers by insisting on price cuts of 5% this year and another 5% in 1996, supplier sources say. That's on top of a "3-3-4" for 1992, '93 and '94, respectively, for a cumulative 20% over five years. "They're getting really tough," says one top-level supplier executive. What makes it worse, he says, is that Ford reveals the new targets almost in the same breath as it reduces some production schedules. "How do you plan under those circumstances?" he asks. Says another: "They want productivity increases on top of productivity increases."