Not strictly, no. Once you've selected some music, the car player doesn't know which playlist it originally came from. Thus, it can have no concept of next/previous playlist.
However, if you're running v2.0beta, you _can_ navigate to the last selected item in the menu. This will allow you to jump to the playlist you last selected, so you can get to the next/previous one relatively easily.
To do it:
1. Press down once to get to the menu. "Playlists" will be selected.
2. Hold the down button. It will jump to the last item you selected.
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roger