Consumer borrowing plunged in October by a record amount, reflecting a big drop in auto loans.

The Federal Reserve reported Wednesday that Americans’ borrowing fell by $7.2 billion at an annual rate in October, the biggest amount ever in dollar terms, including a record drop of $5.6 billion, at an annual rate, in the category that includes car loans.

The drop took analysts by surprise. They had been expecting that consumer spending would rise at an annual rate of $5 billion in October.

“This is a pay back for the aggressive discounts consumers were offered to buy cars during the summer,” said Mark Zandi, chief economist at Moody’s Economy.com.