Minority car buyers were victims of discriminatory lending practices on their car loans, according to federal authorities who have reached a $98 million settlement with Ally Financial.  Federal officials said that Detroit-based Ally Financial and Ally Bank charged higher interest rates from about 235,000 car loan borrowers who were Hispanic, African-American, and Asian/Pacific Islanders since April, 2011...The Justice Department and the Consumer Financial Protection Bureau said an investigation into Ally's lending practices found that car dealers who arranged loans were allowed to mark up the interest rate over what would be justified by their credit profile.  The dealers and Ally split the additional interest payments...Ally will pay an $18 million penalty in addition to $80 million to compensate customers...Ally issued a statement saying its dealers' contracts doesn't include information on a consumer's race or ethnicity, and that it doesn't believe its dealer network was deliberately discriminating. "Regardless, Ally takes the assertions by the CFPB and DOJ very seriously and has agreed to the terms in the orders," it said.