By Brian O’Connell

It’s all champagne and caviar for automakers, as U.S. car, SUV and truck sales are at an eight-year high. Fiat Chrysler reported sales up 20% so far in 2014, while BMW reported an 11% gain through August.

Overall, auto industry sales are at 17.5 million at an annualized rate for 2014 — the best pace for auto sales since the beginning of 2006.

Activity isn’t as glowing is in the financing end, where more consumers are late on car payments and taking on auto loan debt they may not be able to afford.

So says Transunion, the Chicago credit rating firm. It reports U.S. loan delinquency rates up 9% in the second quarter on a year-to-year basis, while total U.S. consumer auto loan debt has increased for 13 consecutive quarters.

The company considers consumers delinquent if they’re 60 or more days late on an auto loan payment. Only 0.095% of all auto loan borrowers fit into that category, but more could be on the way given the historically high rates of auto loan debt.

“Auto lending remains similar to what we have observed during the last several quarters,” says Peter Turek, a vice president at TransUnion. “Delinquency rates remain relatively low while auto loan balances keep rising — both metrics aided by increasing auto loan originations.”

Those higher balances and higher late payment rates are related, Turek says.

“In fact, there are 4 million more auto loan accounts in the marketplace than we observed just last year,” he says. “This means with more auto loans in the marketplace and a delinquency rate ticking higher, we now have several thousand more delinquent accounts than at the midpoint of 2013.”

If you worry about your own auto loan delinquency, contact your lender right away to see if they offer a payment protection plan in case of a missed payment or two (or more.)

Also, see if you can’t refinance to lower your monthly payments. Auto loan rates for a three-year deal are at 3.050%, according to BankingMyWay.com’s auto loan rate tracker.