(Reuters) – U.S. total new vehicle retail sales are expected to decline in December as high vehicle prices and rising borrowing costs pushed consumers to cut back spending, a report from industry consultants J.D. Power-LMC Automotive showed on Wednesday. “Elevated pricing, coupled with repeated interest rate increases, continue to inflate monthly loan payments,” said Thomas King, president of the data and analytics division at J.D. Power. The average monthly payment for a new vehicle loan in December was $718, up $47 from a year ago, per the report. Retail sales of new vehicles this month are …