It probably depends on the player, but when I was looking I saw a couple with USB ports that said they only supported drives up to 4gb or so.

Since the mid-2010s, fewer and fewer new cars have been decked out with CD players. In-dash stereos are instead usually equipped with the long-standing car radio and some kind of media playback option ...

DEARBORN, Mich. - CD players in automobiles could go the way of eight-track tapes with in-dash systems like one Ford Motor Co. and Microsoft Corp. are jointly producing to link cars with cell phones ...