Delinquencies on subprime loans made by non-bank lenders are soaring toward crisis levels. : Private-equity firms that plunged headlong into subprime auto lending are discovering just how hard it might be to get out. A Perella Weinberg Partners fund has been sitting on an IPO of Flagship Credit Acceptance for two years as bad loan write-offs push it into the red. Blackstone Group has struggled to make Exeter Finance profitable, despite sinking almost a half-billion dollars into the lender since 2011 and shaking up the C-suite multiple times.