Michigan\'s public universities have offered thousands of sparsely attended classes, allowed thousands of students to pad grades by taking the same classes over and over, and sometimes failed to monitor or correct faculty performance. Those findings -- issued in state audits -- suggest that taxpayer-supported universities could do more to control costs in dire economic times. The auditors\' concerns come as students and parents face stiff annual tuition increases. In spot checks at six universities, auditors found more than 3,800 instances of students taking the same course three or more times. More than 1,500 Wayne State University students did so, mainly to replace poor or incomplete grades, a practice auditors suggested was an inefficient use of taxpayer money. Beginning next fall, Wayne State students must get permission from academic advisers before taking courses a third time.