Travelling on the California Zephyr in June from San Francisco. I want to book the Amtrak Thruway shuttle from downtown San Francisco to Emeryville. This was not offered during the booking process. When I put in 'San Francisco Salesforce Plaza' to 'Emeryville station' in the booking grid, it returns saying there are no trains for that itinerary (I ***KNOW THAT****, I just want to book the shuttle!!) - any advice where to start?