The good people at Cars.com have slogged their way through sales data from April and found something interesting. The Toyota Prius Plug-In managed to walk away as the third quickest-selling car in the U.S., spending just five days on dealer lots. That figure was good enough to land it behind the BMW X3 and X5 , both of which take four days to find a new homes. The plug-in hybrid has only been on sale for two months, and took the honor of being the second-quickest selling vehicle in March, according to Cars.com.The report also took the time to look at the slowest-selling models around. Surprisingly, the Porsche Boxster sits at the top of that list, taking a whopping 250 days to turn. The 2012 BMW 6 Series isn't doing much better. The 650i Convertible took fourth place with an average of 128 days on the lot while the 640i Coupe rounds out the top 10 with 111 days. Perhaps even more shocking is the news that there are four vehicles selling slower than the Nissan Murano Cross Cabriolet at 120 days on dealer lots. Head over to Cars.com for the full report.