What should I do if the dealer calls saying my financing fell through?

Stay calm and ask for the explanation in writing. Review your signed contract and any conditional-delivery or financing contingency documents to see what they allow. You aren't necessarily required to accept new terms; options may include returning the car and getting your down payment and trade-in back, depending on your state's rules and contract. Contact your state attorney general, the CFPB (consumerfinance.gov), or an attorney if something seems wrong.