More than one million users visit the site each month from a mobile device.
Autotrader.com has launched an enhanced mobile site for the 1m+ users who visit the site each month from a mobile device.
The new site offers more advanced searching, sorting and viewing features.
Jose Puente, director of mobile products, AutoTrader.com said: "There's a new generation of shoppers among us, and their use of mobile devices is growing quickly.
"Mobile shoppers have different needs and expectations when they're using their smart phones than when they're using a computer, and the significant enhancements we made for the new mobile site were designed with those needs and expectations in mind."
The number of unique visitors accessing AutoTrader.com from a mobile device has increased substantially year-over-year,
"We're proud of the growth that we've seen in the usage of our mobile site," said Puente. "For the millions of shoppers who access AutoTrader.com from mobile devices each year, these new features should be a welcomed addition to their car shopping."