Most drivers can tell you their monthly car payment to the dollar, but few can say whether they purchased a vehicle service contract or GAP coverage, according to a new Caribou survey of 2,000 Americans who secured an auto loan this year.

The majority (71%) of respondents can’t recall whether their auto loan includes a vehicle service contract or extended factory warranty, equal to the share who don’t know if they have GAP coverage, according to the survey. Among drivers who say they declined those products, not being able to afford the extra monthly cost was the top reason cited, not a conscious decision to self-insure.

Analysts note 70% of drivers can recall their exact monthly payment without checking paperwork, but only 25% can recall from memory the total interest they’re paying over the life of the loan. Caribou estimates Americans overpay $54 billion a year on auto loans, largely because most drivers accept the first rate offered without shopping multiple finance sources.

Two-thirds of surveyed drivers report at least one unexpected car-related expense in the past 12 months, and 38% say those costs added up to $500 or more. One in three drivers has lost or had to replace a car key; nearly two-thirds of that group had no key replacement coverage.

Read the full report at Caribou