Facebook Marketplace has been around for a year now. In that time, the social network has gotten a firm grasp on what users are buying and selling on its Craigslist rival. (It's also made sure to stop you from hocking certain things like, ahem, hedgehogs). But, cute critters were always going to be a niche category anyway. What's really popping on Marketplace are cars. And, soon Facebook will give you even more ways to track down and purchase vehicles. It's integrating listings from leading car sales and research websites (including Edmunds, Cars.com, Auction123, CDK Global and SocialDealer) to help you find your next ride.