Michael Corkery & Jessica Greenberg:

The loans were for used Dodges, Nissans and Chevrolets, many with tens of thousands of miles on the odometer, some more than a decade old.
 
 They were also one of the hottest investments around.
 
 So many asset managers clamored for a piece of a September bond deal made up of these loans that the size of the offering was increased 35 percent, to $1.35 billion. Even then, Santander Consumer USA received more than $1 billion in investor demand that it could not accommodate.
 
 Across the country, there is a booming business in lending to the working poor — those Americans with impaired credit who need cars to get to work. But this market is as much about Wall Street’s perpetual demand for high returns as it is about used cars. An influx of investor money is making more loans possible, but all that money may also be enabling excessive risk-taking that could have repercussions throughout the financial system, analysts and regulators caution.