Forget housing, there is a new subprime problem in America unrelated to single-family properties.

Credit bureau TransUnion says the seriously delinquent rate for auto loans (or percentage of auto loans more than 60 days past due) edged up to 0.88% in the first quarter, up from 0.82% in Q1 2012. 

The uptick arrives as more subprime borrowers fall behind on payments.

The delinquency rate for subprime auto borrowers alone grew from 5.09% in the first quarter of 2012 to 5.50% in Q1 2013.

"We've been monitoring the auto loan landscape closely for some time to see if increased subprime lending would start pushing delinquency rates up," said Peter Turek, vice president of automotive for TransUnion. 

"We found that while subprime borrowers are receiving more auto loans, the percentage of these loans to all auto loans made remains the same as last year so there has not been a dramatic effect to the overall delinquency rate." 

Subprime borrowers made up 15% of all auto loan accounts in the first quarter of 2013.