It's the age of online shopping, and a few years ago, the race was on to establish the Amazon of used cars. Things haven't played out that way though, and the likes of Carvana have been rocked by the used car market not going their way. Now, major competitor Vroom has officially scuttled its online used car sales business, and will liquidate its inventory.The news was announced both through Vroom's website and a press release seen by Automotive News. Vroom said it's suspending all its online car...