How strange we seem to be missing some posts. Including the one I made yesterday.
Dan,
What time does the flight you are looking at arrive in SAP. You may need to arrive the day before and stay in the hotel like those coming from the US.
You will be able to make the 13:15 departure on the way home as the bus will get to SAP around 11am which gives you enough time to checkin.
Let me know if I can help further.
Cheers
Rich