You can zap between stations in the particular list, from which you have chosen a station or podcast to listen to, e.g. you have clicked on a station from the list 'Recently played', 'Favorites' or from a list of search results. Then, while the station is playing, click on the small station logo in the player above. The Car Mode Player will then open, allowing you to zap to and fro between stations in the chosen list.
For iPads this zapping view is always available at the right side of the screen.