The U.S. auto safety watchdog, toughening its stance against manufacturer defects, announced on Sunday a record $105 million in fines against Fiat Chrysler Automobiles NV over lapses in safety recalls involving millions of vehicles.

The Italian-U.S. automaker's consent agreement with the National Highway Traffic Safety Administration contains an unprecedented buyback option covering hundreds of thousands of vehicles, including more than 1 million Jeep sport utility vehicles, whose owners can receive a trade-in or a financial incentive to get their vehicles repaired.

Fiat Chrysler also agreed to submit to an independent monitor's audit of its recall performance over a three-year period.